Journal of Bodywork and Movement Therapies Official journal of the: ® Association of Neuromuscular Therapists, Ireland ® Australian Pilates Method Association ® Hands On Seminars, USA ® National Association of Myofascial Trigger Point Therapists, USA ® Pilates Foundation, UK Volume 15 Number 4 2011 EDITOR-IN-CHIEF
Leon Chaitow ND, DO
c/o School of Life Sciences, University of Westminster, 115 New Cavendish Street, London W1M 8JS, UK Preferred mailing address: P.O.Box 41, Corfu, Greece 49100 (
[email protected])
ASSOCIATE EDITORS Geoffrey M. Bove, DC, PhD Kennebunkport, ME, USA (
[email protected]) John Hannon DC San Luis Obispo, CA, USA (
[email protected]) Glenn M. Hymel EdD, LMT Department of Psychology, Loyola University, New Orleans, LA, USA (
[email protected])
Dimitrios Kostopoulos PT, MD, PhD, DSc Hands-on Physical Therapy, New York, NY, USA (
[email protected]) Craig Liebenson DC Los Angeles, CA, USA (
[email protected])
ASSOCIATE EDITORS: PREVENTION & REHABILITATION Warrick McNeill MCSP London, UK (
[email protected])
Matt Wallden MSc, Ost, Med, DO, ND London, UK (
[email protected])
International Advisory Board D. Beales MD (Cirencester, UK) C. Bron PhD MPT (Groningen, The Netherlands) I. Burman LMT (Miami, FL, USA) E. Calenda, RMT (Boulder, USA) J. Carleton PhD (New York, USA) F. P. Carpes PhD (Uruguaiana, RS, Brazil) Susan Chapelle (Squamish, Canada) Z. Comeaux DO FAAO (Lewisburg, WV, USA) P. Davies PhD (London, UK) J. P. DeLany LMT (St Petersburg, FL, USA) M. Diego PhD (Florida, USA) J. Dommerholt PT, MS, DPT, DAAPM (Bethesda, MD, USA) J. Downes DC (Marietta, GA, USA) C. Fernandez de las Peñas PT, DO, PhD (Madrid, Spain) T. M. Field PhD (Miami, FL, USA) P. Finch PhD (Toronto, ON, Canada) T. Findley MD, PhD (New Jersey, USA) D. D. FitzGerald DIP ENG, MISCP, MCSP (Dublin, Ireland) S. Fritz LMT (Lapeer, MI, USA)
G. Fryer PhD. BSc., (Osteopath), ND (Melbourne City, Australia) C. Gilbert PhD (San Francisco, USA) C. H. Goldsmith PhD (Hamilton, ON, Canada) S. Goossen BA LMT CMTPT (Jacksonville, FL, USA) S. Gracovetsky PhD (Ocracoke, NC, USA) M. Hernandez-Reif PhD (Tuscaloosa, AL, USA) P. Hodges BPhty, PhD, MedDr (Brisbane, Australia) B. Ingram-Rice OTRLMT (Sarasota, FL, USA) D. Jing-xing PhD, MD (Guangzhou, China) J. Kahn PhD (Burlington, VT, USA) R. Lardner PT (Chicago, IL, USA) P. J. M. Latey APMA (Sydney, Australia) E. Lederman DO PhD (London, UK) D. Lee BSR, FCAMT, CGIMS (Canada) D. Lewis ND (Seattle, WA, USA) W. W. Lowe LMT (Bend, OR, USA) J. McEvoy PT MSC DPT MISCP MCSP (Limerick, Ireland) L. McLaughlin DSc PT (Ontario, Canada) C. McMakin MA DC (Portland, OR, USA)
J. M. McPartland DO (Middleburg, VT, USA) C. Moyer PhD (Menomonie, WI, USA) D. R. Murphy DC (Providence, RI, USA) T. Myers LMT (Walpole, ME, USA) C. Norris MSc CBA MCSP SRP (Sale, UK) N. Osborne PhD DC (Bournemouth, UK) B. O’Neill MD (North Wales, PA, USA) J. L. Oschman PhD (Dover, NH, USA) D. Peters MB CHB DO (London, UK) M. M. Reinold PT, DPT, ATC, CSCS (Boston, MA, MD, USA) G. Rich PhD (Juneau, AK, USA) C. Rosenholtz MA, RMT (Boulder, CO, USA) R. Schleip PhD, MA, PT (Munich, Germany) J. Sharkey MSc, NMT (Dublin, Ireland) D. Thompson LMP (Seattle, WA, USA) C. Traole MCSP, SRP, MAACP (London, UK) P. W. Tunnell DC, DACRB (Ridgefield, CT, USA) E. Wilson BA MCSP SRP (York, UK) A. Vleeming PhD (Schoten, Belgium)
Officially recognised and supported by: The Alliance of Massage Therapy Education The American Massage Therapy Association Associated Bodywork and Massage Professionals The British Orthopaedic Association The Institute of Sport and Remedial massage The International Association of Structural Integrators The International College of Applied Kinesiology USA The International Society of Clinical Rehabilitation Specialists The New Zealand Manipulative Physiotherapists Association The Organisation of Chartered Physiotherapists in Private Practice The Rolf Institute The Sports Massage Association The Upledger Institute
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Journal of Bodywork & Movement Therapies (2011) 15, 395e396
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EDITORIAL
JBMTs new section with a fascial focus e Starting 2012 Previous editorials have emphasised the importance of the role of fascia in our attempts to better understand human function and dysfunction. In March 2012 the Third Fascia Research Congress, in Vancouver Canada, will once again bring together scientists and clinicians in a unique example of collaboration and enquiry across professional boundaries. http://www.fasciacongress.org/2012/. JBMT and its publisher, Elsevier, have actively supported the work of these conferences, and as a further demonstration of this, starting with the first issue of 2012, JBMT will include a section dedicated to both clinical fascial approaches, as well as pure science research, into fascia. A number of leaders in this field have agreed to contribute to this new section, and it is hoped that the special focus that this feature offers will encourage other researchers and clinicians, to do likewise. Among papers that will appear in this section in the first few issues of 2012, currently either in preparation or already In Press, are the following: Nigel Simmonds DC (in press) and colleagues, from the Anglo-European College of Chiropractic, propose that a biologically plausible mechanism that may generate a significant component of the observed effects of manual therapies of all descriptions, is the therapeutic stimulation of fascia in its various forms within the body. They have set out a what they state is a testable framework which links fascia into the therapeutic benefits provided by either high velocity, low amplitude manipulation, as well as soft tissue and mobilization approaches. This paper is In Press e available on ScienceDirect Hans Chaudhry and colleagues have developed a mathematical model to determine the relationship between stretch and the orientation of fibers in the fascia. This paper is an example of a scientific approach where the clinical implications can be translated from the findings. Since it provides a means to model manual therapy interventions in both longitudinal and transverse directions, this may allow more precise 1360-8592/$36 ª 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2011.07.002
specification of manual therapy techniques e such as myofascial release methods. This paper is In Press e available on ScienceDirect Geoff Bove PhD and Susan Chapelle (in press) RMT have studied the possibility of using manual techniques to both prevent and treat abdominal adhesions. The results of their work has demonstrated that, in a rat model, “visceral mobilization may have a role in the prevention and treatment of post-operative adhesions”. (This paper is In Press e available on ScienceDirect Moshe Solomonow PhD MD(Hon) and colleagues, from the University of Colorado, Denver, have compiled a review of extracted data from Solomonow’s over 25 years of (animal and human) research into what he terms Acute Repetitive Lumbar Syndrome, something the authors note to be “common in individuals engaged in long term performance of repetitive occupational/sports activities involving the spine”. Solomonow et al hypothesise that repetitive flexion strains damage collagen fibres in viscoelastic structures, together with simultaneous changes in reflexive neuromuscular function, and consequent stability problems. Inflammation and degenerative changes follow, leading to disability. Finally suggestions are offered relevant to prevention and treatment. This paper Acute repetitive lumbar syndrome; a comprehensive insight into the disorder e is currently being typeset Robert Schleip PhD of the University of Ulm, has studied the effects of isometric stretching on the stiffness of lumbodorsal fascia. Simply stated, stretching that does not produce microtrauma results in extrusion of fluid leading to reduced stiffness, which is subsequently taken up again, restoring stiffness, sometimes more so than was previously the case. The conclusions suggest that tissue hydration is a major feature in tissue stiffness, something of considerable importance in the stability of the low back. The clinical implications of these studies e relative to the lumbodorsal fascia of humans e remains to be confirmed, as the fascia in these reported studies were either murine or porcine.
396
Editorial However, as Dr Schlep points out, there is supporting evidence deriving from MRI studies of the Achilles tendon showing water extrusion during loading followed by subsequent rehydration (and stiffening). This paper: Strain hardening of fascia: Static stretching of dense fibrous connective tissues can induce a temporary stiffness increase accompanied by enhanced matrix hydration, is currently being typeset
A number of additional papers, where fascia is the main focus, are being reviewed or prepared for publication. This issue of JBMT contains another example of fascial focus, in a clinical setting. Tozzi et al. (2011) employed dynamic ultrasound evaluation to demonstrate that gentle manual methods [“low load, long duration stretch along the lines of maximal fascial restrictions”] are capable of releasing areas of impaired sliding fascial mobility, while also modifying pain. The list of papers summarised above should offer a clear sense that while fascia/connective tissue features large in all of them, their range and variety demonstrate that they
have clinical relevance in almost all manual and movement therapies e which is precisely the objective of the new fascia section.
References Bove, G., Chapelle, S. Visceral mobilization can lyse and prevent peritoneal adhesions in a rat model. doi: 10.1016/j.jbmt.2011. 02.004, in press. Simmonds N. et al. A theoretical framework for the role of fascia in manual therapy. Journal of Bodywork & Movement Therapies. 10.1016/j.jbmt.2010.08.001, in press. Chaudhry H. et al. Mathematical model of fiber orientation in anisotropic fascia layers at large displacements, in press. Tozzi, P., et al., 2011. Fascial release effects on patients with nonspecific cervical or lumbar pain. Journal of Bodywork & Movement Therapies 15 (4), 405e416.
Leon Chaitow, ND DO , Editor-in-Chief JBMT, PO Box 41, Corfu 49100, Greece E-mail address:
[email protected]
Journal of Bodywork & Movement Therapies (2011) 15, 397 available at www.sciencedirect.com
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LETTER TO THE EDITOR
Correspondence re “Association of manual muscle tests and mechanical neck pain: Results from a prospective pilot study”
Dear Editor, I appreciate the fact that Cuthbert et al. (2011) have made a preliminary attempt to determine the validity of the Applied Kinesiology (AK) method of using muscle testing to determine the presence of a cervical pain disorder. Further, I am aware that this was a pilot study. However, I think the authors have erroneously concluded that their study provides evidence of the sensitivity and specificity of Applied Kinesiology manual muscle testing for determining who has cervical pain and can at best say that they have found that such research is feasible. One fundamental problem with this study is that the examiners were not blind to the status of the subjects (Straus et al., 2005). The knowledge of the clinical status of the patients means that this study design is prone to confirmation bias (Graber et al., 2005). That is that the examiner finds what the examiner believed they would find, that people with cervical pain have “weak” cervical muscles. Another fundamental problem with this study is that the healthy subjects were not tested by the same examiner who tested the subjects with cervical pain (Straus et al., 2005). Given the fact that we have no way of knowing if the forces applied by the two examiners were even of the same order of magnitude let alone reasonably similar we cannot be certain that the healthy subjects and those with cervical pain were actually tested in the same way. Finally, sensitivity and specificity are normally calculated by using a reference test (in this case the patient’s report of cervical pain or not) comparing it to the findings of the new test (in this case AK muscle testing) (Straus et al., 2005). However this was not done. Sensitivity and
DOI of original article: 10.1016/j.jbmt.2010.11.001. 1360-8592/$36 ª 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2011.06.005
specificity were calculated by some unknown method separately for those with cervical pain and those without. I have no idea how the sensitivity and specificities were calculated. The Journal of Bodywork & Movement Therapies subscribes to the ethical principles of the Declaration of Helsinki and states in their instructions to authors that: “The manuscript should contain a statement that the work has been approved by the appropriate ethical committees related to the institution(s) in which it was performed and that subjects gave informed consent to the work.” The authors do write “all participants were made aware of the experimental details prior to assuming their involvement in the study, and they were required to fill out a symptom questionnaire and consent form before the testing was administered.” (JBMT, 2011) I cannot find any statement that this study was approved by the appropriate ethical committee. Was this just an oversight on both the authors’ and the reviews part, or did I miss this statement?
References Cuthbert, S.C., Rosner, A.L., McDowall, D., 2011. Association of manual muscle tests and mechanical neck pain: results from a prospective pilot study. J. Bodyw. Mov. Ther. 15 (2), 192e200. Apr. Graber, M.L., Franklin, N., Gordon, R., 2005. Diagnostic error in internal medicine. Arch. Intern. Med. 11;165 (13), 1493e1499. Journal of Bodywork and Movement Therapies, 2011. Guide for Authors. Elsevier B. V. [cited June 15, 2011]; Available from: http://wwwelsevier.com/wps/find/journaldescription.cws_ home/623047/authorinstructions. Straus, S.E., Richardson, W.S., Glasziou, P., Haynes, R.B., 2005. Evidence-based medicine: How to practice and teach EBM, third ed. Elsevier Churchill Livingstone, New York.
Stephen M. Perle, DC, MS University of Bridgeport College of Chiropractic, Bridgeport, CT 06604, USA E-mail address:
[email protected]
Journal of Bodywork & Movement Therapies (2011) 15, 398 available at www.sciencedirect.com
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LETTER TO THE EDITOR
Response to Letter to the Editor by Perle To the Editor, We appreciate Dr. Perle’s interest in our recent publication, attempting to establish the validity of manual muscle testing in instances of cervical pain. While pointing out several cautionary notes common to clinical research, we have reason to believe that in this instance they are all misplaced in the four arguments that he has put forth: 1. Blinding: While blinding is a standard criterion of quality in traditional allopathic randomized controlled trials, its inclusion in trials involving physical medicine interventions is known to be highly problematical and in this instance could conceivably be considered to be sort of a blindman’s bluff (Rosner, in press). Furthermore, blinding has actually been known to have a detrimental effect on recruitment for clinical trials (Hemminiki et al., 2004) taking into consideration more recent data which suggest that patient choice and awareness are desirable inclusions rather than the liability that Dr. Perle suggests (Rosner, in press). Finally, blinding has no place in standard clinical practice where manual muscle testing occurs and may actually introduce an unwanted element of stress. If research is to be effectively translated into practice, our attention needs to be focused more upon translational research (Editorial, 2009) rather than the more artificial conditions imposed by blinding. 2. Different examiners: While patients with or without mechanical neck pain were tested by separate examiners, robust data exists to suggest that a substantial degree of inter-observer reliability exists in manual muscle testing (Cuthbert and Goodheart, 2007; Caruso and Leisman, 2000). 3. Sensitivity and specificity: The standard calculation for sensitivity is TP/TP þ FN, while for specificity it is TN/ FP þ TN where TP Z true positive, TN Z true negative, FP Z false positive, and TN Z true negativedprecisely the numbers that were included in our paper. The reference values used in our calculations were the actual occurrences of neck pain as reported by the patient. DOI of original article: 10.1016/j.jbmt.2011.06.005. 1360-8592/$36 ª 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2011.06.006
4. Ethical principals: Patient rights and safety in clinical research are well protected by the principles of the Nuremberg and Helsinki conventions. Indeed, patients were given full informed consent of the experimental details in this study and signed off to that effect. However, in situations such as this in which no experimental interventions of any kind were imposed, ethical committees and internal review boards are essentially irrelevant. This is simply because data from everyday patient appointments with their treating doctor were gathered retrospectively with no risk to, or imposition upon, the patient. In JBMT, as in most of the journals publishing research involving manual medicine, case and case-series reports are frequently published. Dr. Perle’s insistence on an “institutional review board’s” approval of all research printed in JBMT and elsewhere would have censored most of the research conducted in manual medicine for the past century. In conclusion, we believe that the criticisms raised by Dr. Perle with regard to this study can readily be addressed.
References Caruso, W., Leisman, G., 2000. A force/displacement analysis of muscle testing. Percep. Mot. Skills 91, 683e692. Cuthbert, S.C., Goodheart, G.J., 2007. On the reliability and validity of manual muscle testing: a literature review. Chiropractic & Osteopathy 15, 4. Editorial, 2009. [Translational research: two-way traffic]. J. Bodywork Move. T. Ther. 13, 295e296. Hemminiki, E., Hovi, S.L., Veerus, P., Sevon, T., Tuimala, R., Rahu, M., Hakama, M., 2004. Blinding decreased recruitment in a prevention trial of postmenopausal hormone therapy. J. Clin. Epidemiol. 57 (12), 1237e1243. Rosner, A., (in press). Evidence-based medicine: Revisiting the pyramid of priorities. J. Bodywork Movement Ther.
Anthony L. Rosner Scott Cuthbert* Donald McDowall Chiropractic Health Center, 255 West Abriendo Avenue, Pueblo, CO 81004, USA *Corresponding author. Tel.: þ1 719 544 1468. E-mail address:
[email protected] (S. Cuthbert)
Journal of Bodywork & Movement Therapies (2011) 15, 399e404
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CASE SERIES
Changes in pain and pressure pain sensitivity after manual treatment of active trigger points in patients with unilateral shoulder impingement: A case series ˜as, PT, MSc, ´sar Ferna ´ndez-de-las-Pen Amparo Hidalgo-Lozano, PT a, Ce b,c, d * ´lez-Iglesias, PT, PhD e, PhD , Lourdes Dı´az-Rodrı´guez, PhD , Javier Gonza ˜a, PhD f, Manuel Arroyo-Morales, MD, PT, PhD a Domingo Palacios-Cen a
Department of Physical Therapy, Universidad Granada, Spain Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Universidad Rey Juan Carlos, Alcorco´n, Madrid, Spain c Esthesiology Laboratory of Universidad Rey Juan Carlos, Alcorco´n, Spain d Department of Nursing, Health Sciences School, Universidad Granada, Spain e Centro de Fisioterapia Integral, Candas, Asturias, Spain f Department of Health Sciences II, Universidad Rey Juan Carlos, Alcorco´n, Spain b
Received 6 October 2010; received in revised form 30 November 2010; accepted 1 December 2010
KEYWORDS Shoulder impingement; Manual treatment; Trigger points; Pressure pain
Summary The aim of this case series was to investigate changes in pain and pressure pain sensitivity after manual treatment of active trigger points (TrPs) in the shoulder muscles in individuals with unilateral shoulder impingement. Twelve patients (7 men, 5 women, age: 25 9 years) diagnosed with unilateral shoulder impingement attended 4 sessions for 2 weeks (2 sessions/week). They received TrP pressure release and neuromuscular interventions over each active TrP that was found. The outcome measures were pain during arm elevation (visual analogue scale, VAS) and pressure pain thresholds (PPT) over levator scapulae, supraspinatus infraspinatus, pectoralis major, and tibialis anterior muscles. Pain was captured pre-intervention and at a 1-month follow-up, whereas PPT were assessed pre- and post-treatment, and at a 1-month follow-up. Patients experienced a significant (P < 0.001) reduction in pain after treatment (mean SD: 1.3 0.5) with a large effect size (d > 1). In addition, patients also experienced a significant increase in PPT immediate after the treatment (P < 0.05) and one month after discharge (P < 0.01), with effect sizes ranging from moderate (d Z 0.4) to large (d > 1).A significant negative association (rs Z 0.525; P Z 0.049) between the increase in
* Corresponding author. Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Avenida de Atenas s/n, 28922 Alcorco ´n, Madrid, Spain. Tel.: þ 34 91 488 88 84; fax: þ34 91 488 89 57. E-mail address:
[email protected] (C. Ferna ´ndez-de-las-Pen ˜as). 1360-8592/$ - see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.12.003
400
A. Hidalgo-Lozano et al. PPT over the supraspinatus muscle and the decrease in pain was found: the greater the decrease in pain, the greater the increase in PPT. This case series has shown that manual treatment of active muscle TrPs can help to reduce shoulder pain and pressure sensitivity in shoulder impingement. Current findings suggest that active TrPs in the shoulder musculature may contribute directly to shoulder complaint and sensitization in patients with shoulder impingement syndrome, although future randomized controlled trials are required. ª 2010 Elsevier Ltd. All rights reserved.
Introduction Shoulder pain is a common health problem that has a multifactorial underlying pathology with high direct costs for the society (Meislin et al., 2005). The one-year prevalence of shoulder pain ranges from 20% to 50% in the general population (Pope et al., 1997; Luime et al., 2004). Among the different causes of shoulder pain, the most prevalent diagnosis is shoulder impingement (13%) (Pribicevic et al., 2009). The aetiology of shoulder impingement is not completely understood, but there is evidence showing the role of the shoulder musculature as a potential factor (Tyler et al., 2005). Different studies have shown the presence of muscle imbalance of the shoulder musculature in this painful condition (Ludewig and Cook, 2000; Moraes et al., 2008). Due to this imbalance, Simons et al. (1999) suggested that muscle trigger points (TrP) can play a relevant role in shoulder impingement syndrome. TrPs are defined as hypersensible spots in a taut band of a skeletal muscle, painful on contraction, stretching or manual stimulation which give rise to a referred distant pain. Active TrPs are those which their local and referred pains are responsible for the patients’ symptoms. There is preliminary evidence suggesting that referred pain from active TrPs may be implicated in the clinical picture of shoulder impingement. Ingber (2000) described 3 patients with shoulder impingement syndrome who were successfully treated with TrPs injection of the subscapularis muscle. Ge et al. (2008) described the presence of active TrPs within the infraspinatus muscle in individuals with shoulder pain, without specific diagnosis. A recent study reported that the referred pain elicited by active TrPs in the supraspinatus, infraspinatus, pectoralis mayor and subscapularis muscles reproduced the pain pattern in subjects with shoulder impingement (HidalgoLozano et al., 2010). The hypothesis that active TrPs may be relevant for shoulder pain has been supported by the study of Hains et al. (2010) where myofascial therapy using ischemic compression on shoulder TrPs reduced the symptoms of patients experiencing chronic shoulder pain. Therefore, these studies suggest that referred pain from active TrPs may be relevant for shoulder pain. Hidalgo-Lozano et al also found that patients with shoulder impingement exhibit generalized pressure pain hypersensitivity as compared to controls (Hidalgo-Lozano et al., 2010). In addition, the presence of mechanical pain hypersensitivity was related to the presence of active TrPs, suggesting that active TrPs may be involved in sensitization mechanisms in individuals with impingement syndrome (Hidalgo-Lozano et al., 2010). The aim of this case series was to investigate changes in pain and pressure pain sensitivity after manual treatment of active muscle
TrPs in the shoulder musculature in patients with unilateral shoulder impingement.
Methods Patients Consecutive patients with diagnosis of strictly unilateral impingement syndrome stage I (acute inflammation and either tendonitis or bursitis) (Frieman et al., 1994) within the dominant-right hand were recruited. Patients were eligible if: 1) they had unilateral shoulder complaints with duration of at least 3 months; 2) an intensity of at least 4 on an 11-point numerical pain rating scale (NPRS) during arm elevation; 3) positive Neer test, that is, pain during passive abduction (Neer, 1983); and, 4) positive Hawkins, that is, pain when the arm is flexed at 90 and passively positioned in internal rotation (MacDonald et al., 2000). The sensitivity and specificity for the Neer test has been estimated as 79% and 53%, respectively, and for the Hawkins test 79% and 59%, respectively (Hegedus et al., 2008). Patients were excluded if they exhibited any of the following criteria: 1, bilateral shoulder symptoms; 2, younger than 18 or older than 65 years; 3, history of shoulder fractures or dislocation; 4, cervical radiculopathy; 5, previous interventions with steroid injections; 6, fibromyalgia syndrome (Wolfe et al., 1990); 7, previous history of shoulder or neck surgery; or 9, any type of physical intervention for the neck-shoulder area the previous year. The study was approved by the local Ethics Committee (UC 2009-45) conducted following the Helsinki Declaration. All participants signed an informed consent prior to their inclusion.
Outcome measures In this study, a visual analogue scale (VAS) (Jensen et al., 1999) was used to assess the intensity of pain experienced during arm elevation pre-intervention and one month after discharge. The VAS is a 10 cm line anchored with a “0” at one end representing “no pain” and “10” at the other end representing “the worst pain imaginable”. Patients placed a mark along the line corresponding to the intensity of the symptoms, which was scored to the nearest centimetre. It has been shown to be reliable and valid for assessing pain intensity (Bijur et al., 2001), and it was selected as outcome measure based on its ability to detect immediate changes in pain exhibiting a minimal clinically important difference (MCID) between 0.9 cm and 1.1 cm (Bird and Dickson, 2001; Gallagher et al., 2001).
Changes in sensitivity after treatment of active trigger points In addition, pressure pain thresholds (Vanderweeen et al., 1996) (PPT: minimal amount of pressure where a sensation of pressure first changes to pain) over the levator scapulae (2 cm superior to the superior angle of the scapula bone), supraspinatus (middle point over the fosa of the scapula), infraspinatus (middle muscle belly), pectoralis major (middle point under the clavicle bone), and tibialis anterior (halfway between the most superior attachment and its tendon in the upper one third of the muscle belly) muscles were also assessed. To investigate general hypoalgesic effects of TrP interventions, the inclusion of PPT assessment over the tibialis anterior was needed. In this study, a mechanical pressure algometer (Pain Diagnosis and Treatment Inc.ª, Great Neck, NY) was used (kg/cm2). The mean of 3 trials over each point was calculated and used for analysis. A 30-s resting period was allowed between each trial. The reliability of pressure algometry has been found to be high the same day (ICC Z 0.91 [95% CI 0.82e0.97]) (Chesterson et al., 2007) and between 4 separate days (ICC Z 0.94e0.97) (Jones et al., 2007). PPT levels were assessed pre-intervention, post-intervention and one month after discharge.
Myofascial/muscle TrP therapy None of the patients were taking any preventive drug at the time the study was performed. Participants were asked to avoid any analgesic or muscle relaxant during which the study was conducted. Patients were treated by a clinician with more than 6 years of clinical experience in the management of shoulder disorders. All participants attended the physical therapy clinic 2 days per week for 2 weeks (4 sessions). They received the following manual therapies depending on clinical findings related to the location of the TrP. Subjects were examined for the presence of active TrPs in the levator scapulae, supraspinatus, infraspinatus, subscapularis, and pectoralis major muscles by a clinician with more than 5 years of experience in the management of TrPs. TrP diagnosis was conducted according to Simons et al. (1999): 1) palpable taut band in a skeletal muscle; 2) hyperirritable tender spot in the taut band; 3) local twitch response elicited
Figure 1 (1999).
401 by the snapping palpation of the taut band; and 4) presence of referred pain in response to TrP compression (Fig. 1). These criteria, when applied by an experience assessor, have obtained a good inter-examiner reliability (kappa) ranging from 0.84 to 0.88 (Gerwin et al., 1997). Bron et al. (2007a,b) evaluated patients with shoulder pain and found that the most reliable feature of TrP was the referred pain (percentage of pair-wise agreement 70%, range 63e93%). Different manual approaches have been proposed for the management of muscle TrPs (Dommerholt and McEvoy, 2010). A recent systematic review found moderate strong evidence supporting the use of TrP pressure release for immediate pain relief of muscle TrPs (Vernon and Schneider, 2009). In the current study, patients received a TrP pressure release technique over each active TrP that was found (Fig. 2). Pressure was applied over TrPs until an increase in muscle resistance (barrier) was perceived by the clinician and maintained until the clinician perceived release of the taut band (Lewit, 1999). At this stage the pressure was increased to return to previous level of muscle tension and the process was repeated for 90 s (usually 2 to 3 repetitions). Patients also received a neuromuscular technique (longitudinal stroke) (Chaitow, 2010) over the affected muscle, particularly supraspinatus, infraspinatus, and pectoralis major muscles. The thumb of the therapist was placed over the taut band and longitudinal strokes were applied slowly with moderate pressure which was not painful for the patient. This technique has been found to be effective for reducing TrP pressure sensitivity (Iba ´n ˜ez-Garcı´a et al., 2009). TrP manual therapies were applied depending on clinical findings related to the location of the TrP on the affected arm. No pre-determined TrP location was considered.
Statistical analysis Data were analysed with the SPSS statistical package (19.0 Version). Results are expressed as mean, standard deviation (SD) or 95% confidence interval (95% CI). Due to the small sample size and the nature of the data, the use of nonparametric tests was considered robust. The non-parametric Wilcoxon signed test was used to examine differences from baseline to each time point for VAS and PPT levels. Further,
Referred pain from infraspinatus (left) and supraspinatus (right) muscle trigger points (TrPs) according to Simons et al.
402
A. Hidalgo-Lozano et al.
Changes in pressure pain sensitivity
Figure 2
TrP pressure release over infraspinatus TrPs.
changes in VAS and PPT were stratified by gender using the non-parametric U-Mann Whitney test. In addition, to further investigate if changes were clinically relevant, effect sizes were calculated using Cohen d coefficient (d ) (Cohen, 1988). Effect sizes of 0.2 are considered as small, 0.5 as moderate and 0.8 large (Cohen, 1988). Finally, the Spearman’s rho (rs) was used to investigate the associated between changes in pain intensity and changes over PPT over each point at before and one month after treatment. The statistical analysis was conducted at 95% confidence level and a P < 0.05 was considered statistically significant.
Results
The repeated Wilcoxon signed test revealed a significant effect for changes over the levator scapulae (z Z 2.040; P Z 0.041), supraspinatus (z Z 2.047; P Z 0.042), infraspinatus (z Z 2.353; P Z 0.019), pectoralis major (z Z 2.080; P Z 0.038), and tibialis anterior (z Z 2.041; P Z 0.040) muscles. Patients experienced a significant increase in PPT immediate after treatment and one month after the discharge (P < 0.05). Again, no significant differences for PPT difference scores between genders were found for the levator scapulae (t Z 0.622; P Z 0.523), supraspinatus (t Z 0.723; P Z 0.486), infraspinatus (t Z 1.672; P Z 0.125), pectoralis major (t Z 0.372; P Z 0.718), and tibialis anterior (t Z 0.972; P Z 0.502) muscles. Table 1 summarizes PPT levels at each point at pre-, post- and 1 month after discharge, whereas Table 2 shows pre-post changes for PPT data.
Relationship between changes in pain and pressure pain sensitivity A significant negative association (rs Z 0.525; P Z 0.049) between the increase in PPT over the supraspinatus muscle and the decrease in pain was found: the greater the decrease in pain, the greater the increase in pressure pain threshold.
Discussion Clinical data of the participants Twelve patients, 7 men and 5 women, aged 20e38 years (mean: 25 9 years) diagnosed with unilateral shoulder impingement participated. All patients reported pain located in the anterior and posterior parts of the shoulder and the dorso-lateral aspect of the forearm in 5 patients (42%). The mean duration of shoulder pain history was 8.7 4.8 months (95%CI 5e12.4), and the mean intensity of pain experienced during arm active elevation was 5.1 1.9 (95% CI 3.9e6.4).
Changes in pain The Wilcoxon signed test revealed a significant effect (z Z 2.511; P Z 0.011) for pain. Patients experienced a significant reduction in pain (mean SD: 1.3 0.5, 95% CI 0.9e2.3) from pre-intervention (mean SD: 5.1 1.9, 95% CI 3.9e6.4) as compared to one month after discharge (mean SD: 3.8 1.3, 95% CI 2.3e5.2). The effect size for pain was large (d > 1). No significant differences between men and women (t Z 0.781; P Z 0.453) for changes in pain were found. Table 1
The current case series has shown that manual treatment of active TrPs within the shoulder muscles reduces spontaneous pain and increases PPT levels in individuals with shoulder impingement. Current results underline the importance of inspection and inactivation of active muscle TrPs in the shoulder musculature in patients with shoulder impingement syndrome as they may contribute to the overall picture of pain; however, future randomized controlled trials are required to further confirm this assumption. In fact, two randomized controlled trials have been proposed in order to elucidate the role of inactivation of muscle TrPs in patients with shoulder impingement syndrome (Bron et al., 2007a,b; Perez-Palomares et al., 2009). The rotator cuff is formed by the supraspinatus, the infraspinatus, the teres minor and the subscapularis muscles (Keating et al., 1993). In the current case series, active myofascial TrPs in the supraspinatus, infraspinatus, and subscapularis were manually treated. A previous study found that the presence of active TrPs in the supraspinatus and infraspinatus muscles was related to a greater intensity of pain in patients with shoulder impingement, which support the role of active TrPs within the clinical pain
Pressure pain thresholds (PPT, kg/cm2) pre-intervention, post-interventon and one month after discharge. Pre-intervention
Levator scapulae muscle Supraspinatus muscle Infraspinatus muscle Pectoralis major muscle Tibialis anterior muscle
1.9 2.3 2.0 1.2 4.2
0.9 1.0 0.8 0.4 0.9
(95% (95% (95% (95% (95%
CI CI CI CI CI
Post-intervention 1.3e2.5) 1.7e3.0) 1.5e2.5) 1.0e1.4) 3.7e4.9)
2.5 2.8 2.9 1.7 4.6
0.8 0.7 1.4 0.6 1.9
Values are expressed as means standard deviation (95% confidence interval)
(95% (95% (95% (95% (95%
CI CI CI CI CI
One month after discharge 2.1e3.1) 2.4e3.3) 2.0e3.8) 1.3e2.0) 3.4e5.9)
2.8 3.0 2.9 1.8 4.9
0.9 0.8 1.0 0.4 1.9
(95% (95% (95% (95% (95%
CI CI CI CI CI
2.2e3.4) 2.5e3.5) 2.25e3.5) 1.5e2.1) 3.7e6.2)
Changes in sensitivity after treatment of active trigger points Table 2
403
Pre-post and pre-follow/up change scores and effect sizes for pressure pain thresholds (PPT, kg/cm2) Pre-post change scores
Levator scapulae muscle Supraspinatus muscle Infraspinatus muscle Pectoralis major muscle Tibialis anterior muscle
0.6 0.5 0.9 0.5 0.4
0.8 0.9 1.0 0.7 0.8
(95% (95% (95% (95% (95%
CI CI CI CI CI
0.3e1.6) 0.2e1.0) 0.4e1.4) 0.2e0.9) 0.2e1.1)
Pre-post effect size
Pre-follow/ up scores
0.75 0.45 0.90 0.64 0.50
0.9 0.7 0.9 0.6 0.7
1.0 0.9 0.7 0.3 1.0
(95% (95% (95% (95% (95%
Pre-follow/ up effect size CI CI CI CI CI
0.3e1.5) 0.2e1.3) 0.4e1.3) 0.4e0.7) 0.4e1.6)
0.90 0.78 1.10 2.00 0.70
Values are expressed as means standard deviation (95% confidence interval)
picture of these patients (Hidalgo-Lozano et al., 2010). In the current case series one month after 4 sessions of treatment, patients exhibited a decrease of 1.3 cm on pain which surpassed the MCID. Nevertheless, it should also be noted that lower bound estimation for the 95% confidence interval fall in the reported MCID of 0.9e1.1 cm (Bird and Dickson, 2001; Gallagher et al., 2001). Hence, current results should be considered with caution. These findings support the view that active TrPs in the shoulder musculature may contribute directly to shoulder pain complaint in individuals with shoulder impingement syndrome, although future randomized controlled trials are required. It has been previously reported that subjects with shoulder impingement exhibit both segmental and widespread sensitization mechanisms and that this mechanisms are related to the presence of active TrPs and pain symptoms (Hidalgo-Lozano et al., 2010). Shah et al. (2005, 2008) demonstrated that active TrPs constitutes a focus of peripheral sensitization as higher levels of algogenic substances such as bradykinin, substance P, or serotonin, are found in active TrPs as compared with non-TrPs. In addition, Li et al. (2009) recently demonstrated the existence of nociceptive and non-nociceptive hypersensitivity at muscle TrPs. Hence, it would be expected that treatment of active TrPs would reduce this sensitization. The current case series support this hypothesis as moderate to large increases in PPT levels were found one month after the intervention. Nevertheless, although effect sizes support a clinical effect over mechanical sensitivity; we recognize that MCID of PPT levels has not been previously studied. Our results support that muscle TrP treatment can decrease pressure pain hypersensitivity, which is in agreement with two previous studies that demonstrated that TrP treatment induces segmental anti-nociceptive effects (Srbely et al., 2008, 2010). In fact, Hsieh et al. (2007) showed that dry needling of active TrPs in the infraspinatus muscle decreased the pain intensity and mechanical pain sensitivity on the treated arm in patients with shoulder pain, supporting this anti-nociceptive effect. Additionally, the fact that PPT levels also improved in distant pain-free areas, e.g. tibialis anterior muscle, indicates a generalized anti-nociceptive effect of TrP therapy, which has been previously suggested (Niddam et al., 2007). Nevertheless, the association between the decrease in pain and the increases in PPT levels was weak. Finally, we should recognize some limitations to the current case series. First, a study without a comparison group does not allow for inferences to be made regarding cause and effect. Therefore, as result of a lack of control group, we cannot determine if changes in pain and pressure
sensitivity were due to the intervention. Second, we only include a small number of patients with shoulder impingement, which limit the results. Therefore, Future randomized clinical trials are now needed (Bron et al., 2007a,b; Perez-Palomares et al., 2009). Thirdly, we only examined the effects 1-month after discharge, so we do not know the long-term effects of the intervention. The fact that statistically significant changes occurred at short-term follow-up provides impetus for future research in this area.
Conclusion This case series suggests that manual treatment of active TrPs may reduce spontaneous pain and increase PPT in patients with shoulder impingement. Effect sizes were large for pain and moderate-large for changes in PPT. Current findings suggest that active TrPs in the shoulder musculature may contribute to shoulder complaint and sensitization in patients with shoulder impingement syndrome. However, due to a small sample size and the absence of a control group, these assumptions should be consider with caution.
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Journal of Bodywork & Movement Therapies (2011) 15, 405e416
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CLINICAL RESEARCH
Fascial release effects on patients with non-specific cervical or lumbar pain Paolo Tozzi, Bsc (Hons) Ost, D.O., FT a,*, Davide Bongiorno, M.D., D.O. b, Claudio Vitturini c a
Centro di Ricerche Olistiche per la Medicina Osteopatica e Naturale, C.R.O.M.O.N., Via Pasquale Fiore 18, Rome, Italy1 Andrew Taylor Still Academy Italia, A.T.S.A.I., Bari, Naples, Milan, Italy2 c Universita` la Sapienza - Dipartimento di Psicologia, Rome, Italy b
Received 14 January 2010; received in revised form 22 November 2010; accepted 24 November 2010
KEYWORDS Connective tissue; Real-time ultrasound; Fascial imaging; Soft tissue manipulation; Pain perception; Osteopathy
Summary Background: Myofascial Release (MFR) and Fascial Unwinding (FU) are widely used manual fascial techniques (MFTs), generally incorporated in treatment protocols to release fascial restrictions and restore tissue mobility. However, the effects of MFT on pain perception, and the mobility of fascial layers, have not previously been investigated using dynamic ultrasound (US) in patients with neck pain (NP) and low back pain (LBP). Objectives: a) To show that US screening can be a useful tool to assess dysfunctional alteration of organ mobility in relation to their fascial layers, in people with non-specific NP or LBP, in the absence of any organ disease; b) To assess, by dynamic US screening, the change of sliding movements between superficial and deep fascia layers in the neck, in people with non-specific NP, before and after application of MFTs c) To assess, by dynamic US screening, the variation of right reno-diaphragmatic (RD) distance and of neck bladder (NB) mobility, in patients with nonspecific LBP, before and after application of MFTs d) To evaluate ‘if’ and ‘at what degree’ pain perception may vary in patients with NP or LBP, after MFTs are applied, over the short term. Methods: An Experimental group of 60 subjects, 30 with non-specific NP and 30 with nonspecific LBP, were assessed in the area of complaint, by Dynamic Ultrasound Topographic Anatomy Evaluation (D.US.T.A.-E.), before and after MFTs were applied in situ, in the corresponding painful region, for not more than 12 min. The results were compared with those from the respective Sham-Control group of 30 subjects. For the NP sub-groups, the pre- to post- US recorded videos of each subject were compared and assessed randomly and independently by two blinded experts in echographic screening. They were asked to rate the change observed in the cervical fascia sliding motions as ‘none’, ‘discrete’ or ‘radical’. For the LBP sub-groups,
* Corresponding author. Via Festo Avieno 150, 00136, Rome, Italy. Tel.: þ39 3486981064 (mobile); fax. þ39 06 97749900. E-mail address:
[email protected] (P. Tozzi). 1 www.cromon.it. 2 www.atsai.it. 1360-8592/$ - see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.11.003
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P. Tozzi et al. a pre- to post- variation of the right RD distances and NB mobility were calculated on US imaging and compared. For all four sub-groups, a Short-Form McGill Pain Assessment Questionnaire (SF-MPQ) was administered on the day of recruitment as well as on the third day following treatment. Results: The Chi square test has shown a significant correlation (0.915) with a p-Value < 0.0001 between the two examiners’ results on US videos in NP sub-groups. The ANOVA test at repeated measures has shown a significant difference (p-Value < 0.0001) within Experimental and Control groups for the a) pre- to post- RD distances in LBP sub-groups, b) pre- to post- NB distances in LBP sub-groups; as well as between groups as for c) pre- to post- SF-MPQ results in NP and LBP sub-groups. Conclusions: Dynamic US evaluation can be a valid and non-invasive instrument to assess and monitor effective sliding motion of fascial layers in vivo. MFTs are effective manual techniques to release area of impaired sliding fascial mobility, and to improve pain perception over a short term duration in people with non-specific NP or LBP. ª 2010 Elsevier Ltd. All rights reserved.
Introduction Fascia and MFTs Fascia is a connective tissue organized in a three-dimensional network, that surrounds, supports, suspends, protects and connects muscular, skeletal and visceral components of the body. Studies suggest that fascia reorganizes along the lines of tension imposed or expressed in the body at both molecular (Dunn and Silver, 1983; Mosler et al., 1985) and macroscopic level (Sasaki and Odajima, 1996). Myers (2000) describes fascial meridians as tensile myofascial bands, that comprise a single continuous structure. From this perspective, the repercussion of a fascial restriction may be body-wide, and may potentially create stress on any structures enveloped by fascia (Greenman, 1989). The consequent distortion of the body’s threedimensional alignment may lead to biomechanically inefficient function (Rolf, 1977). It has been suggested that fascial strains can slowly increase, requiring progressive body adaptation at a local and global level (Levin, 1990). The pressure exerted with subsequent stress on the surrounding soft tissues may have mechanical and physiological effects. This is evident mechanically in the collagenous framework of the body, which is organized as a tensegritive structure (Levin, 1990), as well as at the cellular level (Ingber and Chen, 1999; Pischinger, 1991). The ground substance changes to a more ‘sol’-like consistency (the fluid state of living colloids, reversible into a more solid, ‘gel’-like state), while fibrous infiltration and cross links between collagen fibers may develop at the nodal points of fascial bands, together with a progressive loss of elastic properties (Chaitow, 1999). Fascial techniques aim to release such tensions, decrease pain and restore function. The proposed mechanism for fascial techniques is based on various studies that looked at the plastic, viscoelastic and piezoelectric properties of connective tissue (Fratzl, 2008). As the collagen fibers are released, they reorganize themselves in the underlying substance, whose viscosity changes so permitting tissue remodelling (Cantu and Grodin, 1992). This change in viscosity seems to involve an increase in the production of hyaluronic acid, together with the flow of as well as
improved drainage of inflammatory mediators and metabolic wastes (Schultz and Feltis, 1996); together with reduced chemical irritation of the ANS endings and nociceptive stimuli to somatic endings (Lund et al., 2002; Mense, 1983). To better understand the clinical implications of fascial restrictions in cases of acute and chronic NP or LBP, the quality of sliding motion between fascial layers in vivo appears to be of great importance (Langevin 2006). FU is a commonly used, but seldom researched, technique in osteopathic practice (Ward, 2003), aimed to release fascia restrictions and to restore tissue mobility and function. MFR is defined by Manheim (2001) as the facilitation of mechanical, neural, and psychophysiological adaptive potential as interfaced via the myofascial system. It represents a widely employed manual technique specific for fascial tissues, to reduce adhesions, restore and/or optimise fascia sliding mobility in both acute and chronic conditions (Barnes, 1996; Martin, 2009; Sucher, 1993; Walton, 2008). Some studies have shown the efficacy of MFR to decrease pain, improve posture, and quality of life (Barnes, 1990; Fernandez de las Penas et al., 2005; LeBauer et al., 2008; Lukban, 2001; Radjieski et al., 1998). However, according to Remvig (2008) “There are no published reliability studies documenting that the diagnostic method is reproducible and valid.”
US screening In many different studies and areas of practice, US is widely used to screen and diagnose for various: a) Acute (Nelson et al., 1980) and chronic conditions (De Miguel et al., 2009; Falsetti et al., 2004): infective (Gandolfo et al., 1993; Harr et al., 1982; Simons et al., 1983), genetically transmitted (Heckmatt et al., 1982), inflammatory (Karabay et al., 2007; Kenney and Hafner, 1977), degenerative (Heers and Hedtmann, 2002) and neoplastic (Nishimura et al., 1992) diseases; b) As well as to perform real-time investigation of dysfunctional syndromes, still not well-understood by other methods of screening (Cvitkovi c-Kuzmi c et al., 2002; Wong and Li, 2000).
Fascial release effects on patients with non-specific cervical or lumbar pain US is also shown to be a reliable tool: c) To assess the presence and the extent of surgery-related sequelae (Ku ¨llmer et al., 1997; Mann et al., 1989; Wiener et al., 1987), as well as the consequences of traumatic injuries (Bokhari et al., 2004; Murphy et al., 2005); d) To monitor the procedure of invasive techniques of investigation and surgical intervention (Bassi et al., 1996; Gandolfo et al., 1993; Sinha and Chan, 2004); e) To evaluate the follow up of patients under manual therapies in real-time (Hutzschenreuter et al., 1989; Park et al., 2007; Quere ´ et al., 2009; Torstensen et al., 1994), or under specific therapeutic protocols (Wang et al., 2008); f) To treat musculo-skeletal conditions when applied in a therapeutic form (Dogru et al., 2008; Downing and Weinstein, 1986; Esposito et al., 1984). However, few studies have relied on US screening to investigate alterations of the mobility of organs on their fascial layers, and even fewer have related such impaired mobility with pain on the correspondent spinal level. No research has ever assessed, by real-time US screening, any possible change in vivo of the range of sliding movements between superficial and deep fascial layers, before and after MFTs are applied in situ, on patients with non-specific NP or LBP: as has been the scope of this study. US screening of cervical organs mobility in patients with NP e Hypothesis 1 (H1) Up to now, most of research has assessed thyroid mobility, esophageal motility and larynx mobility, by US screening, in people with NP in concomitance of a disease of the organ observed: thyroid mobility and shape have been evaluated in patient complaining of NP and suffering of subacute thyroiditis (Yamashita et al., 1993) and thyroglossal duct abscesses (Rohn and Rubio, 1980); additionally, esophageal sensory and motor function has been studied by US investigation, in dysfunctional (Hirano and Pandolfino, 2007), pathological (Takebayashi et al., 1991) as well as in normal conditions (Mittal, 2005); mobility and anatomy of the healthy larynx and perilaryngeal structure have been observed by US screening (Valente et al., 1996) mainly in the paediatric field (Friedman, 1997). For the scope of this study, instead, the general mobility of cervical organs within the superficial and deep fascia complexes of the neck were investigated in relation to non-specific NP, in the absence of any cervical organ disease, before and after MFTs were applied in situ. Because the patient’s discomfort or pain should be taken in account as clinically relevant phenomena, in addition, this study has questioned whether changes in fascial mobility, following manual therapy, might influence pain perception in symptomatic patients. Thus this study’s first hypothesis: H1: i) US screening can be used to assess a dysfunctional alteration of cervical organ mobility on their fascial layers, in people with non-specific NP and without cervical organ disease; ii) The application of MFTs to the symptomatic cervical region improves the quality and quantity of such fascial layers mobility, observable by US screening; iii) The application of MFTs decreases NP perception in the short term.
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US screening of kidney and bladder mobility in people with LBP e Hypothesis 2 of this study (H2) Research has shown the relation between lumbar pain and altered renal mobility and shape in patients with frank acute (Barbagelata Lo ´pez et al., 2008) and chronic (Rivera et al., 2008) kidney pathology, as well as in cases of inherited (Bajwa et al., 2004) and acquired conditions (Watkins et al., 2009), by using US methods of screening. However, no study has established the criteria for “normal” kidney mobility. There is also no established neither if there is a correlation between renal mobility and lumbar pain in the absence of renal pathologies (although one study (Morgan and Dubbins, 1992) screened for pancreas and, partially, for renal mobility, using US, on patients with unrelated symptomatology). With regard to US assessment of bladder mobility, research studies have investigated the degree of bladder descent in primiparae (Sartori et al., 2004), nulligravid and multiparae (Meyer et al., 1996), as well as in women with stress urinary incontinence (Pregazzi et al., 2002), the latter during both Valsalva manoeuvre and maximal pelvic floor contraction. However, only a few have questioned a relationship between bladder pathology and LBP, such as in a case of bladder prolapse (Heit et al., 2002), or general urological disease (Tilscher et al., 1977). There have been no such studies reported in the absence of bladder pathology. Furthermore, no studies have investigated how back pain perception and kidney/bladder mobility varies after manual therapy is applied, in patients with no frank organic pathologies (the literature reports a preliminary study of chiropractic decompression (Browning, 1989) in six cases with pelvic dysfunction, although clinical signs were used as indicators for pre and post assessment). Therefore, this study has investigated the possible relationship between non-specific LBP and renal/bladder mobility, and their myofascial suspending and supporting structures, in patients with healthy kidneys and bladder, before and after MFTs were applied in situ. In addition, this study has questioned whether possible changes in fascial mobility, following manual therapy, may influence pain perception in symptomatic patients. Thus this study’s second hypothesis: H2: i) US screening can be used to assess dysfunctional changes in kidney and bladder mobility and their fascial layers, in people with non-specific LBP and without organ disease; ii) The application of MFTs to the symptomatic lumbo-pelvic region improves the quality and quantity of such organs mobility, measurable by US screening; iii) The application of MFTs decreases LBP perception over the short term.
Materials and methods Population During the one year period during which this study was conducted, out of the 356 subjects who came to the clinic presenting with NP or LBP, a total of 120 were recruited after examination and meeting the inclusion criteria. The inclusion criteria were an age between 18 and 60 years; a complaint of non-specific pain in the cervical or lumbar
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region, with or without associated neurological symptoms, with a duration of at least 3 weeks and of not more than 6 months; an MRI/US documented absence of inherited or acquired pathologies of the spine, or the neck, kidneys and bladder. Exclusion criteria were pregnancies, concomitant receipt of physical or manual therapy, the use of analgesics and/or anti-inflammatory drugs in the previous 72 h. Out of the 120 people included in this study, 60 were suffering from non-specific NP, while the remainder reporting non-specific LBP. The subjects were randomly selected and assigned to Experimental and Sham-Control groups. A block randomization was applied at this phase: a block size of 6 was established and a random choice of the possible balanced combination in each block was made to determine the assignment of the two sub-groups (NP and LBP) into their respective main groups (Experimental and Control). The male-female ratio as well as the age range and mean for each group are shown on Table 1.
Setting This study was conducted over a period of 13 months, from September 2008 to October 2009 at the C.R.O.M.O.N. centre in Rome, Italy.
Real-time US screening Each subject underwent a US scanning of the area of complaint, performed by a blinded, medical doctor with 15 years experience of specialised US screening. ESAOTE My LAB 25 GOLD device was used for this purpose. A Dynamic Ultrasound Topographic Anatomy Evaluation (D.US.T.A.-E.) was performed on each subject: This offered a method of US screening that included recordings of real-time US videos, with a specific focus on anatomical margins and morphologies of the organs assessed, together with their effective sliding motion on surrounding connective tissue structures in vivo.
rotation, rested on the couch, before and after MFTs or the sham treatment had been applied. A linear probe was used at 7.5e13 MHz. It was always positioned on the sagittal plane at the left antero-lateral region of the neck, between the sternocleido-mastoid muscle and the ipsilateral neurovascular bundle, as shown in Figure 1. The aim was to observe any quantitative and/or qualitative change in mobility between fascial layers of the neck region, such as pretracheal and retropharyngeal fascia, during quiet respiration, maximal inspiration-expiration, and swallowing, before and after treatment. Two medical doctors, of 19 and 21 years experience in US screening and diagnosis, were asked to compare the results independently. They were blind to the groups (Experimental and Control) from which the images were obtained. After having randomly viewed and compared the pre- and post- US videos for every NP subject, they were asked to rate any possible change in quality and quantity of the cervical fascia sliding motions as ‘none’, ‘discrete’ or ‘radical’. The values obtained by the first examiner were called Ultrasound Qualitative Scale 1 (US-QS1) results, whereas those collected from the second examiner were called Ultrasound Qualitative Scale 2 (US-QS2) results.
Lumbar and pelvic US screening A similar procedure was applied to LBP subjects: with patients supine, the probe was positioned in the lateral lumbar region, for a sagittal scan. A convex probe was used at 5 MHz and THI. The distance between the superior pole of the right kidney and the origin of the respective diaphragmatic crura (RD distance) was taken during both maximal inspiration (RdI) and maximal expiration (RdE), as shown on Figure 2, before and after treatment (see figure 2) was applied. The aim was to measure and compare
Neck US screening A D.US.T.A.-E. was performed on each subject of the NP Experimental and Sham-Control groups in supine position, with the head, in mild extension and right side-bending-
Table 1 A list of the number of subjects, male (M) and female (F), age range and age mean values for each main group (Experimental and Control) and the respective subgroups (NP and LBP) is shown. Study groups
Subjects M F Age range Age mean
Experimental group
Control group
NP
LBP
NP
LBP
30 24 6 23e48 37,3
30 18 12 21e58 39,1
30 20 10 18e56 39,6
30 22 8 28e52 39
Figure 1 Standard procedure for the neck US screening in NP subjects. The standard procedure for US screening of the neck region for NP sub-groups is shown: the patient lies supine with the head resting on the couch, in a mild extension, and right side-bending-rotation. The probe is positioned on the left antero-lateral region of the neck, between the sternocleidomastoid muscle and the ipsilateral neurovascular bundle, along the sagittal plane. A US recorded video was taken during swallowing, quiet and forced breathing, before and after treatment was applied.
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then drink 500 cc. of water an hour before the same session. Bladder filling influences the position and mobility of the bladder neck and the proximal urethra, which are both more mobile when the bladder is nearly empty (Dietz and Wilson, 1999).
Pain assessment
Figure 2 US RD distance measurement on LBP sub-groups. The distance between the superior pole of the right kidney and the origin of the respective diaphragmatic crura was taken during maximal inspiration and expiration in both LBP subgroups, before and after treatment was applied.
pre- to post- range of kidney’s supero-inferior sliding motion, during forced respiration. Successively, the same subjects were also assessed at their pelvic region, in supine position, using the same type of probe. In this case, the probe was always positioned above the pubic symphysis, for transverse and sagittal scanning. The distance between the neck of the bladder and the anterior vesical wall on the perpendicular line (NB distances) was taken during maximal relaxation (NbR) and contraction (NbC) of the pelvic floor muscles, as shown in Figure 3 before and after treatment was applied. All patients were asked to urinate 2 h prior the session and
Pain perception was measured using the Short-Form McGill Pain Assessment Questionnaire (SF-MPQ), a responsive scale giving both reliable and valid data (Melzack, 1987). The SF-MPQ consists in a 15-point descriptor of average pain, articulated in 11 points of sensory experience and 4 of affective experiences. An intensity scale of 0e3 representing mild, moderate or severe pain, is given for each descriptor. The sensory and affective pain rating scores (ranging from 0 to 33 and from 0 to 12 respectively) are added together to give a value for total pain experience (ranging from 0 to 45). The total score has been used as the outcome of this study. The SF-MPQ was administered to every subject on the day of recruitment, as well as three days later.
Osteopathic assessment An Osteopathic assessment was performed by an Osteopath, of 5 years experience, in the symptomatic region of the NP and LBP Experimental subjects, to locate the specific area of major fascial restriction of mobility, respectively in the neck and lumbar regions.
Treatment The Experimental group received MFTs on the painful areas, by the same Osteopath who had previously assessed them. The treatment consisted of application of MFR and FU techniques: MFR treatment MFR consists in the application of a low load, long duration stretch along the lines of maximal fascial restrictions (Barnes, 1990). The latter are palpated by the practitioner and the pressure is applied directly to the skin, into the direction of restriction just until resistance (tissue barrier) is felt. Once found, the collagenous barrier is engaged for 90e120 s, without sliding over the skin or forcing the tissue (Manheim, 2001), until the fascia complex starts to yield and a sensation of softening is achieved.
Figure 3 US NB distance measurement on LBP sub-groups. The distance between the neck of the bladder and the anterior vesical wall, on the perpendicular line, was taken during maximal relaxation and contraction of the pelvic floor muscles in both LBP sub-groups, before and after treatment was applied.
a) For the Experimental NP group: MFR was applied in two stages, for not more then 2 min each. The aim was to release the deep and superficial cervical myofascial structures, having an effect on their reciprocal sliding motion, in both the anterior and the posterior neck region. The hold used with patient supine, was with the operator’s caudal hand on the sternum and the cranial hand on the forehead, when MFR being applied to the anterior neck structures. The cranial hand was supporting the head at the subocciput when MFR was applied to the posterior neck structures (Stanborough, 2004).
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b) For the Experimental LBP group: MFR was applied in two stages, for not more then 2 min each. The aim was to firstly release the right and then left psoas major and minor as well as the iliacus muscles and related lumbar organs, by using the cross-handed hold shown in Figure 4 (Stanborough, 2004). The kidneys are embedded and suspended by the renal fascia that is anatomically related to the diaphragm and psoas fascia, that is in turn a continuation of the thoraco-lumbar fascia (Bogduk, 2005). Secondly, the pelvic floor muscles and related pelvic organs were targeted to be released by the application of MFR through a global pelvic A/P hold. With the patient supine, one operator’s hand on the sacrum, between patient legs, and one hand just above the pubic symphysis (Stanborough, 2004).
FU treatment FU consists in a functional indirect technique: the operator engages the restricted tissues by unfolding the whole pattern of dysfunctional vectors enclosed in the inherent fascial motion. A shearing, torsional or rotational component may arise in a complex three-dimensional pattern that needs to be sensed and unwound until a release is felt (Ward, 2003). a) For the Experimental NP group: MFR treatment was followed by FU of the neck, by using the same holds described above for the MFR technique. The overall FU treatment was applied for not more than 2 min. b) For the Experimental LBP group: MFR treatment was followed by FU of the lumbar and lumbo-pelvic region. With regards to the lumbar region, the hold used is shown on Figure 5. This was applied on both sides. For the pelvic release, the same global A/P hold described above for the MFR technique was used. The overall FU treatment lasted not more than 6 min.
Figure 5 FU hold for LBP Experimental group. The hold used for FU technique applied to the Experimental LBP group is shown: the patient is side lying with the lower leg flexed; the operator behind, facing the patient. The caudal hand supports the upper patient leg with flexed knee. The cranial hand contacts the lateral lumbar region. By using the patient upper leg as a lever, and the cranial hand as a fulcrum, a tissue unwinding is performed aimed to release the psoas muscle, lumbar spine and kidney mobility.
Sham treatment The Sham-Control group blindly received a sham treatment by someone who did not have any knowledge of anatomy or experience in manual therapy whatsoever. a) For the Sham-Control NP group: The sham-osteopath rested his hands on the patient’s neck, for 3 min, by using each of the two A/P holds described above for the MFR technique applied to the Experimental NP group. The sham treatment lasted 6 min in total, as was the case for the Experimental NP group (given by 4 min of MFR and 2 min of FU techniques application). b) For the Sham-Control LBP group: The sham-osteopath rested his hands on the patient’s lumbar and lumbopelvic region, for 4 min, using each of the following holds: left and right cross-hand hold, as shown in figure 4 the global A/P pelvic hold as described above for the MFR technique applied to the Experimental LBP group. The sham treatment lasted 12 min in total, as did the overall treatment for the Experimental LBP group (given by 6 min of MFR and 6 min of FU techniques application).
Ethic committee The research study was approved by the L.U.Me.N.Oli.S ethical committees, related to the institution in which it was performed. All the subjects who took part in the project gave informed consent. Figure 4 MFR hold for LBP Experimental group. The hold used for MFR technique applied to the Experimental LBP group is shown: a cross-handed hold along the psoas, with the cranial hand below the inferior costal margin and the caudal hand above the inguinal region. The aim is to release the psoas and iliacus muscles as well as related lumbar organs.
Statistical analysis All analyses were performed using the software “STATVIEW 5.0” (SAS Institute Inc.) and Microsoft EXCEL for some data graphic representations.
Fascial release effects on patients with non-specific cervical or lumbar pain a) With regards to H1 i) and ii): the results of the US-QS1 and US-QS2 were compared using the Chi square test, with a p value accepted at <0.05. With regards to H1 iii) as well as to H2 i), ii), iii), : the ANOVA test at repeated measures was used, with a p value accepted at <0.05, to calculate if between Experimental and Control groups there was a significant difference for the: b) RD-T0 and RD-T1 distances in LBP sub-groups, by considering RD-T0 Z RdI-T0 RdE-T0 and RD-T1 Z RdIT1 RdE-T1; c) NB-T0 and NB-T1 distances in LBP sub-groups, considering NB-T0 Z NbR-T0 NbC-T0 and NB-T1 Z NbRT1 NbC-T1; d) pre- to post- SF-MPQ results.
Results a) US-QS: The US-QS results (US-QS1 and US-QS2) for the NP study population are shown on Figure 6 with their respective frequency. A significant difference is shown with a p-Value < 0.0001. The Chi square test between USQS1 and US-QS2 results, after they have been normalized in z points, has shown a significant correlation (0.915) with a p-Value < 0.0001 (confirming H1 i) and ii)); b) US kidney values: RD-T0 and RD-T1 distances in the LBP groups are shown on Figure 7 A significant difference is shown with an F-Value Z 76.637 and a p-Value < 0.0001. In the Experimental group the mean value of RD-T0 was 10.33, St. Dev. 4.70, against the RD-T1 mean value of 21.60, St. Dev. 7.06. In the Control group the mean value of RD-TO was 8.93, St. Dev. 2.01, against the RD-T1 mean value of 10.10, St. Dev 4.49. The range of the all RD-T0 values was 3/þ21 mm, mean 9.63, St. Dev. 3.65; the
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range of all RD-T1 values was 2/þ32 mm, mean 15.85, St. Dev. 5.78 (confirming H2 i) and ii)); c) US bladder values: NB-T0 and NB-T1 distances in LBP subgroups are shown on Figure 8. A significant difference is shown with an F-Value Z 577.349 and a p-Value < 0.0001. In the Experimental group the mean values of NB-T0 was 12.70, St. Dev. 4.18, against the NB-T1 mean value of 22.73, St. Dev. 3.73. In the Control group the mean value of NB-TO was 12.20, St. Dev. 3.81, against the NB-T1 mean value of 12.90, St. Dev. 4.23. The range of NB-T0 values was þ4/þ21 mm, mean 12.45, St. Dev. 3.98; the range of NB-T1 values was þ3/þ30 mm, mean 17.82, St. Dev. 3.98 (confirming H2 i) and ii)); d) SF-MPQ: Pre- to post-differences between Experimental (NP þ LBP) and Control (NP þ LBP) groups are shown on Figure 9. A significant difference with an F-Value Z 167.742 and a p-Value < 0.0001 is shown on Table 2. Means and St. Dev. values are shown on Table 3. The mean difference between groups was 4.883; the mean difference between pre- and post- was 4.483. No significant difference was found either between NP and LBP sub-groups (p-Value < 0.8582), or between genders (p-Value < 0.4866) or between age classes (p-Value < 0.5031), with respect to the study population (confirming H1 iii) and H2 iii)).
Discussion This study shows that cervical and some lumbo-pelvic organs mobility, with respect to the surrounding myofascial structures, may be assessed by US screening; that such mobility changes are related with pain in the corresponding spinal area; that such mobility may be reduced or altered without frank organic pathology; that MFTs can improve
Figure 6 Chi square p-Values for US-SQ1 and US-SQ-2 results in NP sub-groups. The US-QS results (US-QS1 and US-QS2) for the NP sub-groups are shown with their respective observed frequency. A significant difference is shown with a p-Value < 0.0001.
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Figure 7 US kidney results in LBP sub-groups. The significant difference between RD-T0 and RD-T1 distances in LBP subgroups are shown. In the Experimental group the mean values of RD-T0 was 10.33, St. Dev. 4.70, against the RD-T1 mean value of 21.60, St. Dev. 7.06. In the Control group the mean value of RD-TO was 8.93, St. Dev. 2.01, against the RD-T1 mean value of 10.10, St. Dev 4.49.
such fascia related organs mobility as well as reduce pain perception over a short term period.
H1 e neck pain, US screening of cervical fascia mobility and MFTs Most research that has investigated the efficacy of manual therapies on subjects with neck pain have used US for sham treatment only, as de-tuned device (Koes et al., 1993; Schwerla et al., 2008), very few as a tool for measurement or monitoring (Licht et al., 1998). This study, instead, shows that US evaluation is a valid, non-invasive method to monitor and assess organs mobility in the cervical and
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Figure 9 SF-MPQ results in the two study group. The significant difference between Experimental and Control groups for the pre- to post- SF-MPQ results is shown.
abdomino-pelvic region, in vivo and real-time. Furthermore, intraluminal impedance and intramural or endoscopic US and ultrasonography have been mainly recruited in the last decades of research, because of advances in transducer technology, computerization, and graphic data presentation. This study also shows that release obtained by MFTs in the superficial and deep myofascial structures of the neck allowed a better motion of the organs related to those structures: a) Radical findings: The two blinded examiners of US recorded videos have both separately indicated as ‘radical’ the change between the same pre and post images, in 7 subjects of the Experimental group, accounting for the 23.33% of the study group, whereas no ‘radical’ change was found in the Control group. b) Discrete findings: a mean value of 15 of ‘discrete’ change was found in the Experimental group, versus a mean value of 1.5 in the Control group c) None findings: With regards to the ‘none’ change, a mean value of 8 was found in the Experimental group, compared to a mean value of 28.5 for the Control group. However, limitations of this part of the study were: a) Method-related: the US property of scanning all planes reduces the chance of standardization (and often of quantification) of distance measurements; b) Examiner-related: because of human margins of error, is extremely difficult to obtain and reproduce two images, ‘pre’ and ‘post’, in the same plane and angulation; c) Patient-related: position, breathing, inter and intra tissue mobility, viscoelastic changes. The need for a mathematical model capable of comparing similar US images is paramount to analyse pre to post changes.
Figure 8 US bladder results in LBP sub-groups. The significant difference between NB-T0 and NB-T1 distances in LBP sub-groups are shown. In the Experimental group the mean values of NB-T0 was 12.70, St. Dev. 4.18, against the NB-T1 mean value of 22.73, St. Dev. 3.73. In the Control group the mean value of NB-TO was 12.20, St. Dev. 3.81, against the NBT1 mean value of 12.90, St. Dev 4.23.
H2 e lumbar pain, US screening of kidney mobility and MFTs This study has also investigated the range of sliding motion of the right kidney in people with lumbar pain and absence of renal pathology, before and after specific MFTs were
Fascial release effects on patients with non-specific cervical or lumbar pain Table 2
ANOVA table for SF-MPQ values.
Gruppl Subject (Group) Category for SF-MPQ Category for SF-MPQ Gruppl Category for SF-MPQ Subject (Group)
DF
Sum of squares
Mean square
1 118 1 1 118
1430.817 18703.033 1206.017 1297.350 912.633
1430.817 158.500 1206.017 1297.350 7.734
applied on psoas muscles and lumbar region. The release followed by the unwinding of the fascial restrictions may have restored the optimal tissue elasticity of the surrounding myofascial structures, rebalanced the intra and inter visceral pressure, re-established an optimal renal mobility, and via fascial continuation, have improved lumbar spine mobility. Although we could concluded that application of MFTs significantly improves kidney mobility and reduces pain perception, at this stage it is inappropriate to state that people with non-specific lumbar pain may present with a relative reduction of right kidney’s mobility, due to the fact that no study has ever assessed “normal” kidney mobility during respiration and/or established an index of kidney mobility. Therefore, no comparison is possible between the values obtained (RD-T0 range values 3/þ21 mm, mean 9.63, St. Dev. 3.65; RD-T1 range values 2/þ32 mm, mean 15.85, St. Dev. 8.25) and those in “normal” conditions.
H2 e lumbar pain, US screening of bladder mobility and MFTs This study has also investigated the range of neck bladder mobility in people with non-specific lumbar pain and a healthy bladder. The restriction identified may have contributed to or maintained LBP, via viscero-somatic reflex, and/or via venous and lymphatic drainage congestion, or more simply via mechanical tension through connective tissue connections (Ward, 2003). In fact, the bladder ‘sits’ on the pelvic floor and is partially supported and suspended by the endopelvic fascia via its extensions, such as the pubovesical ligaments, together with the pubosacral laminae from the levator ani muscle (Paoletti, 2003). MFTs have been shown to be effective at improving bladder mobility, and may have balanced pelvic floor tensions on the transverse and sagittal planes, restoring optimal bladder mobility and possibly general pelvic adaptive capacity. The latter meaning the potential ability of the pelvic girdle and its contents maintain a functional and mechanical balance against possible disrupting action of internal and external forces. This may
Table 3
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Means table for SF-MPQ values. Count Mean
Control, SF-MPQ T0 60 Control, SF-MPQ T1 60 Experimental, SF-MPQ T0 60 Experimental, SF-MPQ T1 60
24.883 25.050 24.650 15.517
Std. Dev. Std. Err. 9.151 8.867 8.582 9.839
1.181 1.145 1.105 1.270
F-Value
P-Value
Lambda
Power
9.027
.0032
9.027
.863
155.933 167.742
<.0001 <.0001
155.933 167.742
1.000 1.000
have offered, in turn, a balanced and mobile support to the lumbar spine, possibly improving its mobility and reducing inflammation and pain. The range of neck bladder mobility found in this study was þ4/þ21 mm, mean 12.45, St. Dev. 3.98 at T0; and þ3/þ30 mm, mean 17.82, St. Dev. 6.35 at T1. Some studies have shown “normal” bladder mobility, although in women only and exclusively with regards to bladder descent during the Valsalva manouvre (Dietz et al., 2004). The degree of mobility was found to range from 1.2 to 40.2 mm (mean 17.4 mm). Other studies (Pregazzi et al., 2002) have, investigated bladder mobility during maximal pelvic floor contraction, using different electronic distance measurements, such as that between the bladder neck and the pubic symphysis, the bladder neck and the symphysis pubis line, the midline of the symphysis (alpha angle) and the angle between the proximal and distal urethra (beta angle). Most of these studies have used perineal ultrasonography that allows far more details and precision than the more traditional external US investigation method chosen for this study. Therefore, comparisons of the results of this study with those from previous ones are inappropriate at this stage. However, much research has relied on US investigations, especially perineal and introital, to assess for prolapses (cystoptosis, bladder neck and urethral mobility), confirming that US remains the first line examination for pelvic morphology and bladder function.
H1 and H2 e neck or lumbar pain and MFTs In both NP and LBP sub-groups, MFTs have shown to be effective in reducing pain perception regardless of age, gender and pain location, with an SF-MPQ mean values of 24.65 at T0 and 15.51 at T1 in the Experimental group against the mean values ranging from 24.88 at T0 to 25.05 at T1 for the Control group. A significant difference was found (p-Value < 0.0001).
Suggestions for further research In this study, pain assessment was performed over a short period of 3 days following treatment, on a relatively small study population (although the small p-values obtained support the statistical notion that the small study population doesn’t minimise the validity of the study itself). Future studies should evaluate whether these findings are reproducible, in a larger population, and whether positive longterm outcomes can be achieved in both US findings and pain assessment. Future research should also consider investigating the effect of MFTs on specific NP or LBP, to evaluate their efficacy when a specific organ pathology is present at the corresponding spinal level. This may help to better
414 understand the potential contribution of organ pathology to a viscero-somatic reflex in the symptomatic area, as well as the potential therapeutic contribution of MFTs to restore normal conditions. The results may also be compared with those collected from other types of physical, pharmacological or surgical interventions. The authors suggest that in further studies, an extra third variable: the subjective perception of the practitioner should be introduced. To date no study has compared simultaneously these three main perspectives: the subjective perception of the patient, the objective values from any sort of device-calculated measurements, and the subjective perception of the therapist on ‘if’ and ‘to what degree’ the tissues were perceived as restricted before treatment or released after. In addition, a real-time US screening may be used during manual technique applied to observe tissue change in vivo during treatment. The analysis of the relationship between these three diagnostic variables would be extremely useful in both clinical and research areas, due to the intrinsic relevance of diagnostic validity and reliability when a treatment effect has been shown.
Conclusions Dynamic US evaluation can be a valid and non-invasive instrument to assess effective sliding motion of fascial layers in vivo. The association between change in fascial/ organ movement and symptoms has been demonstrated, whereas a fascial involvement in both organ function and pain remains plausible at this stage. MFTs appear to be a useful method to improve or even restore normal tissue mobility and function as well as to decrease pain perception. Further studies should demonstrate whether these findings are reproducible, and whether positive long-term outcomes can be achieved.
Conflict of interest statement We hereby assert that there are no actual or potential conflicts of interest including any financial, personal or other relationships with other people or organisations within three years of beginning the submitted work that could inappropriately influence, or be perceived to influence, our work.
Acknowledgements We would like to thank Dr. Paolo Zavarella, D.O., principal of C.R.O.M.O.N. e Rome, and Cosimo Quaranta, D.O. principal of A.T.S.A.I. e Bari, for their support and contribution to make of our efforts a conclusive research study.
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Journal of Bodywork & Movement Therapies (2011) 15, 417e430
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CLINICAL ASSESSMENT
The assessment of the cervical spine. Part 2: Strength and endurance/fatigue Nikolaos Strimpakos, Assistant Professor a,b,* a b
Department of Physiotherapy, TEI Lamias, 3rd Km Old National Road, Lamia-Athens, Lamia 35100, Greece Centre for Rehabilitation Science, University of Manchester, UK
Received 4 May 2010; received in revised form 23 September 2010; accepted 5 October 2010
KEYWORDS Neck pain; Cervical spine; Assessment; Strength; Endurance; Fatigue
Summary Quantitative documentation of physical deficits such as muscle strength and endurance/fatigue in the cervical spine may provide objective information, not only helping the diagnostic procedures, but also monitoring rehabilitation progress and documenting permanent impairments. The reliable and valid evaluation of muscle strength and endurance both in clinical and research environments are a difficult task since there are many factors that could affect the assessment procedure and the obtained values. The aim of the second part of this critical review is to identify the factors influencing the assessment of strength and endurance/fatigue of the muscles in the cervical spine. ª 2010 Elsevier Ltd. All rights reserved.
Introduction Neck muscle strength and endurance/fatigue has been evaluated in both clinical and laboratory settings. The assessment of these factors along with neck range of motion and proprioception (presented in part I of this review) has been proposed from many researchers and clinicians as an important component of a thorough evaluation of the cervical spine that could possibly contribute to the “cause and effect” justification of neck disorders (Jull et al., 1999; Hermann and Reese, 2001; Strimpakos and Oldham, 2001; Dumas et al.,
* Department of Physiotherapy, TEI Lamias, 3rd Km Old National Road, Lamia-Athens, Lamia 35100, Greece. Tel.: þ30 22310 60203. E-mail address:
[email protected].
2001; Nakama et al., 2003; Strimpakos et al., 2004; Puglisi et al., 2004; Lee et al., 2005; Strimpakos et al., 2005a, 2005b, 2006; Kapreli et al., 2007; Nordin et al., 2008; Vaillant et al., 2008; Dvir and Prushansky, 2008; de Koning et al., 2008; Kapreli et al., 2009). On the other hand, debate continues regarding the correlation between pain and strength or endurance/fatigue measurements (Jordan et al., 1997; Ryan et al., 1998; De Loose et al., 2009). It is often difficult to distinguish whether the muscular weakness is the cause of acute or recurrent injury and pain or is a result of the pain itself. One of the main reasons for this discrepancy among clinicians and researchers is the confounding reports in the literature. The ability to measure neck muscle strength or their endurance/fatigue is challenging due to many methodological limitations. In most studies assessing neck muscle
1360-8592/$ - see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.10.001
418 performance, there has been no uniform method or recommendation how to perform the test and/or report the results (Suryanarayana & Kumar 2005; Rezasoltani et al., 2008; Dvir and Prushansky, 2008; de Koning et al., 2008). In order, therefore, to determine the best protocol for measuring muscle strength and endurance/fatigue in the cervical spine this critical review aims to identify the factors influencing their assessments and estimates. A computerised search was performed through the Medline, EMBASE, CINAHL and AMED databases from 1966 to March 2010 using broad as well as specific key words e individually or in combination. They included: cervical spine, neck, function, reliability, validity, intra-observer, inter-observer, strength, endurance and fatigue. This was followed by a search through references cited in the retrieved articles. Only English language articles were included. Reliability and validity studies were included if they reported at least one measurement tool concerning cervical strength, endurance and fatigue, regardless of whether the studies were in healthy or symptomatic subjects. Studies were excluded if measurements were limited to the electromyography-based method (EMG) as the plethora of parameters included in EMG studies highlights the need for a separate comprehensive analysis of this variable.
Strength Neck muscle strength has been used as an indicator of neck dysfunction. Studies concerning the cervical spine have reported reduced muscle strength in patients with neck pain, headache and other neckeshoulder disorders (Silverman et al., 1991; Vernon et al., 1992; Levoska and KeinanenKiukaanniemi, 1993; Watson and Trott, 1993; Jordan and Mehlsen, 1993; Gogia and Sabbahi, 1994; Hamalainen et al., 1994; Nitz et al., 1995; Barton and Hayes, 1996; Jordan et al., 1997; Placzek et al., 1999; Dumas et al., 2001; Chiu and Sing, 2002; Jull et al., 2004; Ylinen et al., 2004a, 2004b; Prushansky et al., 2005; Cagnie et al., 2007; de Koning et al., 2008). Nowadays, there is no consensus among clinicians and researchers regarding the correlation between pain and strength measurements (Ylinen et al., 2004b; De Loose et al., 2009). Much data exist reporting improvements in neck muscle strength and reduction of neck pain after rehabilitation (Highland et al., 1992; Jordan and Mehlsen, 1993; Berg et al., 1994; Ylinen and Ruuska, 1994; Randlov et al., 1998; Nelson et al., 1999; Kay et al., 2005; Falla et al., 2006; O’Leary et al., 2007a; Ask et al., 2009). On the other hand, some authors have stressed that quantification of spinal disease through strength measurements is not valid as strength is poorly correlated with pain and disability both before and after treatment. They also noted that strength measurements are not very reproducible in patients (Waddell et al., 1992; Jordan et al., 1997; Ryan et al., 1998; van den Oord et al., 2010). Recent studies however revealed that impairment, functional limitations (i.e. isometric strength, endurance, ROM) and disability correlated well with each other in patients with cervical spine disorders (Hermann and Reese, 2001; Kay et al., 2005; Lee et al., 2005; Nordin et al., 2008; de Koning et al., 2008).
N. Strimpakos In a review assessing trunk muscle strength Beimborn and Morrissey (1988) suggested that pain may interfere with the ability of a subject to produce a maximum voluntary contraction (MVC) (Beimborn and Morrissey, 1988). Patients fear that they may evoke their painful neck under maximum stress e as strength measurements often demand e thus making these measurements invalid. A number of studies however, have postulated that no serious adverse effects (i.e. pain or injury) have been noted in patients or healthy subjects after maximum isometric voluntary contractions of the neck muscles (Highland et al., 1992; Berg et al., 1994; Ylinen and Ruuska, 1994). Furthermore a more recent publication suggests that the presence of symptomatology in neck patients does not adversely affect the reliability of the physical outcome measures (Sterling et al., 2002). The psychological benefit to the patients after these contractions could also be a significant factor contributing to the pain reduction as they realise that they can use their neck in stressful tasks without fear. The possibility however, of adverse effects after a maximum contraction in patients with neck pain of discogenic origin cannot be eliminated at the moment, as no study has been found in the literature to examine this issue (Kay et al., 2005). As a result of these conflicting opinions about strength and pain correlations, some researchers have suggested that the classical gross measurements of strength and endurance may actually reflect a pain tolerance measure rather than an estimation of muscle function (Mannion et al., 1996). In each instance however, there is a general consensus among clinicians and researchers that strength measurements (regardless if they are primary or secondary outcomes) are of clinical value at least for determining training dosage and documenting rehabilitation efficacy (Leggett et al., 1991; Highland et al., 1992; Pollock et al., 1993; Berg et al., 1994; Ylinen and Ruuska, 1994; Hagberg et al., 2000; Nakama et al., 2003; Ylinen et al., 2004b; Kay et al., 2005). There are many operational definitions of strength. Harris and Watkins (1999) have defined strength as “the ability of skeletal muscle to develop force for the purpose of providing stability and mobility within the musculoskeletal system, so that functional movement can take place”. It has also been interpreted as “the magnitude of the torque exerted by a muscle or muscles in a single maximal isometric contraction of unrestricted duration” (Enoka, 2002) or as “the maximum force that muscles can exert isometrically in a single voluntary effort” (Caldwell et al., 1974; Fulton, 1989). Torque and force are different concepts with torque being the capability of a force to produce axial rotation and is equal to the magnitude of the force times the perpendicular distance between the line of action of the force and the axis of rotation. Force is measured in Newton (N) and torque is measured in Newton meter (N m) (Enoka, 2002). In clinical and experimental settings strength is commonly measured in one of three ways: as the maximum force that can be exerted during an isometric contraction, the maximum load that can be lifted once, or the peak torque during an isokinetic contraction (Enoka, 2002). The isometric contraction task is usually referred to as a maximum voluntary contraction (MVC). The strength values retrieved from an individual therefore, depend on how strength is measured.
The assessment of the cervical spine. Part 2 The measurement methods also vary among investigators and published studies. In clinical practice, manual muscle testing (MMT) is used very often most likely due to low cost and time effectiveness. However, the use of MMT for the assessment of muscular function has been criticised primarily due to the crude measurement scale and its low reliability (Dvir and Prushansky, 2008). On the other hand, the utility of hand-held dynamometers for measuring muscle strength in the cervical spine is also limited since the devices are unable to measure rotation and their reliability and validity are vulnerable to examiner bias (Strimpakos and Oldham, 2001; Dvir and Prushansky, 2008). Isokinetic devices have also been used for measuring cervical spine strength, but up to now manufacturers of isokinetic dynamometers do not supply specialised attachments. Although there are certain advantages for using isokinetic dynamometry the existence of several methodological drawbacks such as the difficulty in aligning the centre of rotation with the mechanical axes of the testing device, the fixation of the subjects on the device, the cost and expertise needed make their utility questionable. Fixed frame dynamometry has been used by the vast majority of investigators. Most of these devices are able to measure isometric strength in flexion, extension and lateral flexion of the cervical spine (Seng et al., 2002; Chiu and Sing, 2002; Garces et al., 2002; Rezasoltani et al., 2008) and some of them can also examine the rotation (Ylinen et al., 1999; Vasavada et al., 2001; Ylinen et al., 2003; Strimpakos et al., 2004; Salo et al., 2006). Unfortunately, there is a great discrepancy among reported values making any conclusion or clinical inference invalid. Several studies have shown that muscle strength is dependant on the type of muscle fibres and is correlated with the cross-sectional area (Mayoux-Benhamou et al., 1989). Also, biomechanical internal and external factors (such as anatomical variation, muscular contraction type, muscle length, speed of contraction, etc) can compromise or enhance the muscles’ ability to produce maximum force. It may also be influenced by factors arising during the measurement procedure such as the position and posture of the subjects, the use of stabilisation and isolation of the cervical spine, the number of repetitions as well as the diurnal variation and hormonal effect on strength production. The importance of each of these factors and their influence in neck muscles’ strength assessment is discussed below.
Factors influencing strength measurements Muscle fibre composition and muscle strength Muscle fibre composition affects the capacity of a muscle to generate force. Based on their biochemical, physiological, and anatomical profiles, skeletal muscle fibres have been classified into two major fibre types: type I (slow-twitch oxidative), and type II which subdivide into type IIA (fasttwitch oxidative glycolytic), type IIB (fast-twitch glycolytic) or type IIC (intermediate or transitional) (Uhlig et al., 1995; Enoka, 2002). In general, fast-twitch (phasic) motor units, which are composed of large motoneurons, large axons and large muscle fibres, demonstrate the shorter time-to-peak
419 tension and are capable of exerting the greatest tensions. Conversely, slow-twitch (tonic) units are composed of small motoneurons, slow transmitting axons, and slowly contracting muscle fibres. The latter are the most resistant to fatigue (Smidt and Rogers, 1982; Murphy, 1993; Harris and Watkins, 1999). Previous studies have confirmed greater type I fibre size and composition in various back muscles (Johnson et al., 1973; Mannion et al., 1998) although few studies have described the histochemistry of human neck muscles, whether in health or disease. Of those studies undertaken, most of them showed that neck muscles (paravertebral group, trapezius, multifidus and longus colli) consist mainly of type I muscle fibres (Lindman et al., 1990; Wharton et al., 1996; Hannecke et al., 2001). Furthermore, differences were observed between the different portions of the trapezius for both genders (the most superior parts of the descending portion indicated a higher frequency of type IIB fibres) but the mean cross-sectional area of the fibres in female muscle was considerably smaller (Lindman et al., 1991). These observations may indicate a lower functional capacity in females which may be of importance in the development of neck and shoulder dysfunction. However, the huge intramuscular and intermuscular variations regarding fibre type composition as well as problems in obtaining cervical muscle biopsy samples make proving the associations between cervical muscle fibre type and force production difficult. Despite these limitations a loose relationship between muscle strength and fibre crosssectional area is described (Jones and Round, 1990).
Functional biomechanics and muscle strength The amount of force generated by the muscles depends on the mechanical factors of muscular contraction type, muscle length, and speed of contraction. A concentric contraction occurs when the force developed by a muscle exceeds the magnitude of the external applied force, resulting in shortening of the whole muscle. An isometric contraction occurs when the force developed by a muscle is equal to the external force. An eccentric contraction occurs when the external force exceeds the force developed by the muscle, resulting in a lengthening of the whole muscle. Muscle length affects the binding capacity between actin and myosin molecules of the component muscle fibres. Maximal force is generated at some midpoint in the range of motion, while less force is developed in either shortened or lengthened positions (Harris and Watkins, 1999). The speed of contraction also affects the binding capacity of actin and myosin. In concentric contractions, greater force is generated as the speed of shortening decreases, becoming maximal at zero velocity e which equates to a static isometric contraction. With eccentric contractions, increasing speed (to the extent permitted by voluntary and neuromotor control) can generate greater force than that generated during isometric contractions. These higher forces may reflect the contribution of the passive elastic components of muscle connective tissues in addition to the contractile mechanism (Harris and Watkins, 1999). These factors should be taken account during any muscle strength assessment and the use of stabilisation methods (such as torso stabilisation) is important for
420 keeping muscle lengths constant in order to provide reliable measures of cervical function.
Moment arm and muscle strength Another factor influencing muscular strength is the moment arm, or perpendicular distance from the line of application of the musculotendinous unit to the axis of rotation for the joint. Principles of mechanics dictate that the greater the musculotendinous moment arm, the greater the strength because the joint torque at a given instant is equivalent to the product of the force output of a muscle and the length of the moment arm. The moment arm of a muscle, and consequently the measured tension, may be altered with changes in joint angle. Many authors have shown that the total moment-generating capacity of the neck muscles change in different neck/head postures (Harms-Ringdahl et al., 1986; Queisser et al., 1994; Hamilton, 1996; Vasavada et al., 1998; Bonney and Corlett, 2002). Changes in posture alter the moment produced by the weight of the head by changing the location of the head’s centre of gravity with respect to the point of rotation in the cervical spine (Figure 1). The lengthetension relationship, combined with moment arm changes throughout the ROM, alters a muscle’s moment or torque-generating capability. Biomechanical models showed that most of the cervical spine muscles maintain at least 80% of their peak force-generating capacity throughout full cervical ROM (Oatis, 2004) and many of them have the advantage of producing the maximum force in the neutral position of the head (Vasavada et al., 1998). The complex anatomy of the head and neck musculoskeletal system make the direct estimation of muscles forces or moment arm impossible. Most efforts are therefore, limited to a gross estimation of neck muscle strength. For isometric strength testing, the magnitude of the force alone is a valid indicator of muscular strength if the point of application, line of application, direction of force, and segment position are kept constant between measurements. If any of these factors are not constant, the measurements should be obtained in the form of a moment or torque (Smidt
N. Strimpakos and Rogers, 1982). The standardisation of the procedure and subject’s position is the most effective way for optimal comparison of measures between sides, between examinations, and between subjects. Researchers and clinicians have to take into account therefore the above considerations and to employ measurement devices that are able to satisfy these requirements. Furthermore, comparisons between results obtained in different investigations can only be made between those utilised the same measurement units (peak force or moment ratios).
Maximum muscle activation The ability of an individual to maximally activate a muscle by voluntary command seems to vary across muscles. Jakobi and Rice (2002) in a study comparing young and old volunteers demonstrated that for elderly men, elbow flexor maximal activation was achieved less frequently than for elbow extensors and muscle activation was more variable than in the young men. However, when sufficient attempts were provided, the best effort in order to achieve maximal voluntary muscle activation for the elderly men was not different from that of the young men for either muscle group (Jakobi and Rice, 2002). This supports the view that, at least for some muscles, maximal activation is theoretically possible through voluntary effort (Jones and Round, 1990). However, it appears that, although humans are capable of recruiting nearly all of the maximal force capability of muscles, there is a significant inter and intraindividual variation in this capability (Allen et al., 1995). If the voluntary command does not evoke the maximum force that the muscle can exert, then neuromuscular electrical stimulation can probably overcome some of the deficit (Enoka, 2002). Unfortunately, electrical stimulation of the neck muscles is not practical for the following reasons. Firstly, although the sensation of slight stinging or biting may be well tolerated in peripheral muscles, it may be difficult to accept in cervical muscles. Secondly, this method is applied only to superficial muscles so the deep synergistic muscles responsible for the contractions in neck
Figure 1 The change of the head posture changes the moment arms and the lengthetension relationship (mechanical advantage) of neck muscles (From Neumann, 2002, with permission).
The assessment of the cervical spine. Part 2 area cannot be stimulated (Herbert and Gandevia, 1999) resulting in false estimations. Thirdly, the presence of many arteries, nerves and muscles in this region may render the technique dangerous and thus inappropriate for use in the cervical spine. The use of voluntary contractions (isometric or dynamic) is therefore unavoidable in the assessment of neck maximal strength. The use of verbal encouragement has been suggested as an additional method for ensuring muscle maximal activation (Johansson et al., 1983; Bohannon, 1987).
Repetitions and maximum muscle contraction It may be that many repetitions are necessary in order to permit subjects to generate a true maximal contraction (Gardiner, 2001; Jakobi and Rice, 2002). Allen et al. (1995) in a systematic study of the intra and inter-individual variability in assessing elbow flexor strength underlined the importance of several repeat measurements in order to determine a maximum contraction (Allen et al., 1995). The study highlighted the variability in maximum strength between contractions which can affect the reliability of repeated measurements. Many studies have reported that several sub-maximum and maximum contractions have to be employed before the actual measurements take place (Smidt and Rogers, 1982). No studies have evaluated the relative effect of the number of repetitions on the cervical muscles’ strength. Some authors have argued that one repetition is enough for producing the maximum strength (Levoska et al., 1992; Peolsson et al., 2001) while in a study yielded by our research team no specific trend concerning the peak values amongst the repetitions was found (Strimpakos et al., 2004). Until future studies address this issue, maximal contractions should be repeated until three are within 10% of each other in order to ensure maximal activation and to avoid undesirable fatigue (Berg et al., 1994; Placzek et al., 1999; Strimpakos et al., 2004).
Warm-up and practice effect on muscle strength In addition to the obvious value of acclimatising the patient to the particular assessment method, preparatory light exercises as a warm-up may induce a number of physiological changes that affect the assessment of muscular strength. A warm-up is associated with increasing muscle temperature, activating intermuscular energy sources, activating hormonal resources, alerting the nervous system (Smidt and Rogers, 1982), disrupting transient connective tissue bond and increasing core temperature (Enoka, 2002). The increase in core temperature will improve the biomechanical performance of the motor system and will enhance higher force production (Stienen et al., 1996; Saez et al., 2007). Conversely, reductions in muscle temperature decrease its work capacity (Wade et al., 2000). Furthermore, warm-up has a protective role in injury prevention and studies have shown that cold muscles are more stiff and possibly predisposed to injury (Best et al., 1997; Bishop, 2003; Woods et al., 2007). Although no clear-cut effects of warm-up on measurements of maximal strength have been established, some form of sub-maximal active warm-up is often recommended as a standard procedure (Smidt and Rogers, 1982). In neck strength measurements this should be routine to
421 eliminate fear and increase confidence (Leggett et al., 1991; Highland et al., 1992; Berg et al., 1994; Strimpakos and Oldham, 2001; Valkeinen et al., 2002; O’Leary et al., 2005). It is also better to keep a constant room temperature during data collection in order to overcome any possible temperature influence. In recent work of our research team, all reliability estimates were better and peak strength values were greater when the first test was excluded from the analysis (Strimpakos et al., 2004). In that study, a practice session preceded the first test and this may have also contributed to reduction of the learning effect. One practice or familiarisation test has been also used by several investigators in both cervical and lumbar spine (Graves et al., 1990; Berg et al., 1994) and seems to be needed even in healthy subjects to establish reliable strength estimates.
Position and movement effect The initial body position for measuring neck muscle strength seems to be very important for the magnitude of the results. Despite the indications that different initial body positions revealed different strength values for both patients and healthy subjects (Gogia and Sabbahi, 1991; Vernon et al., 1992; Levoska et al., 1992; Strimpakos and Oldham, 2001; Kumar et al., 2001; Chiu and Sing, 2002; Strimpakos et al., 2004) only two studies examined the effect of different positions on strength exertion (Gogia and Sabbahi, 1991; Strimpakos et al., 2004). Unfortunately, the values of these studies cannot be compared because of different positions examined (prone versus sitting and sitting versus standing respectively). However, in both studies all positions yielded reliable results but different peak strength values with sitting position producing higher scores. One main reason for these results seems to be the stabilisation system and the compensation from parts of the body other than the cervical spine. Neck extension yields the maximum strength following by flexion and lateral flexion irrespective of age or gender (Kumar et al., 2001; Strimpakos et al., 2004). The exact ratio between movements is not available since the discrepancy between published estimates is great due to the different methods and instruments used, the position of the head during measurements (offering physiologic and mechanical advantage), and the population studied. The placement of load cell especially in flexion can also affect the measurements (Figure 2). Weak deep neck flexors could permit chin protraction altering the muscle-length ratio and compromising the reproducibility and validity of the results (Dvir and Prushansky, 2008). A similar problem exists with the level of thoracic support during extension (Rezasoltani et al., 2008). Thus, one should consider the effect of initial body position and movement when examining the neck strength and comparing data with other investigations. Stabilisation of the trunk for minimizing compensation from other parts of the body is also essential for reliable and valid strength measurements in the cervical spine.
Diurnal variation and muscle strength Many studies have shown that the ability of skeletal muscles to produce maximum force may be affected by time-of-day
422
Figure 2 Measuring neck strength during flexion in sitting (Arch. Phys. Med. Rehabil., 2004; 85:1309e1316, with permission from Elsevier).
influences (Sedliak et al., 2007, 2008). Wyse et al. (1994) demonstrated that peak values during isokinetic leg testing were different throughout the same day and suggested that reliable comparisons between strength values have to be based on data obtained within 30 min of the same time of the day (Wyse et al., 1994). Coldwells et al. (1994) in back and leg strength measurements observed also diurnal variations with the smaller values obtained at the early morning (Coldwells et al., 1994). Currently there are no available studies investigating diurnal variations on cervical muscles but most researchers suggest the measurements should take place the same time on the day to avoid any time-of-day effect (Strimpakos and Oldham, 2001).
N. Strimpakos fatty acid and carbohydrate metabolism which in turn can affect muscle strength and endurance (Astrand and Rodahl, 1986). Gonadotropic hormones (FSH and LH) stimulate the male and female sex organs to grow and secrete their hormones at a faster rate and thus have an indirect effect on muscle strength production. The androgen testosterone (high concentration in males, low in females) is believed to be responsible for increases in muscle mass and strength and also decreases in body fat (McArdle et al., 1991). Hormone influences may therefore play a major role in assessing skeletal muscle function and factors that influence their production should be taken into account. Studies of the effect of women’s reproductive hormones during their menstrual cycle on muscle strength have demonstrated conflicting results. Sarwar et al. (1996) tested skeletal muscle strength, relaxation rate and fatigability of the quadriceps during the menstrual cycle (Sarwar et al., 1996). They found no changes in these parameters for women taking oral contraceptives. For women not taking oral contraceptives, the quadriceps were stronger, more fatigable and had a longer relaxation time at mid-cycle (day 12e18). Phillips et al. (1996) reported a higher adductor pollicis strength during the follicular phase than during the luteal phase, with a rapid decrease in strength around ovulation (Phillips et al., 1996). They suggested that oestrogen has a strengthening action on skeletal muscle, although the underlying mechanism is not clear. Other studies have found no changes in skeletal muscle strength over the menstrual cycle (Lebrun et al., 1995; Gur, 1997). Janse de Jonge et al. (2001) using the twitch interpolation method for ensuring maximal activation of the quadriceps muscle suggested that the fluctuations in female reproductive hormone concentrations throughout the menstrual cycle do not affect muscle contractile characteristics (Janse de Jonge et al., 2001). No studies have been found in the literature regarding the relationship between neck muscles’ contractile properties and different phases of the menstrual cycle. It is recommended that this variable is better controlled during strength assessments by avoiding testing during menstruation. However, more research is needed in order to clarify this issue since, as mentioned above, there is also some evidence for a significant mid-cycle effect.
Implications for clinicians and researchers regarding neck strength assessment
Hormonal influences on muscle strength Hormones are involved in many functions of the body and affect the ability of muscles to produce force (Hoffman, 1999). Growth hormone (GH) has widespread physiological activity because it promotes cell division and cellular proliferation throughout the body. GH facilitates protein synthesis, muscle growth and contributes to one’s ability to perform endurance exercise. Insulin, and its antagonist glucagon, regulates total body glucose metabolism and stimulates the process of gluconeogenesis. Both hormones however, seem to have a greater effect during prolonged exercise than during maximum strength development. The adrenal gland hormones (catecholamines, mineralocorticoids, glucocorticoids) have a profound influence on free
Similar to the assessment of neck ROM, the evaluation of neck strength is influenced by the complexity of the cervical spine. The use of a stabilisation system in order to ensure the same subject torso and head position in any measurement is important. Neck extensors can produce higher forces than flexion or lateral flexion muscles and this trend can be used as an indicator for valid results. All assessments should also be performed after undertaking warm-up exercises and a full practice session at the same time of the day and preferably not early morning. Hormonal influences such as the menstrual cycle have to be considered in muscle strength evaluation in women. Finally, giving motivation of the subjects with loud and consistent commands is essential for obtaining maximum activation of the muscles.
The assessment of the cervical spine. Part 2
423
Endurance/fatigue
Methods for assessing neck endurance/fatigue
Neck pain is usually associated with sustained static loading and the function of neck muscles depends on their strength and endurance. Studies have shown that a lower endurance ability and reduced neuromuscular efficacy of the neck muscles (especially of deep neck flexors) is a common finding in patients with neck pain, headache and chronic cervicobrachial syndrome (Hagberg et al., 2000; Alricsson et al., 2001; Jull et al., 2004; Falla et al., 2004a; Falla et al., 2004c; Lee et al., 2005; Peolsson and Kjellman, 2007; Nordin et al., 2008; de Koning et al., 2008; Jull et al., 2009; Kalezic et al., 2010). Although strength and endurance are separate phenomena, they are interrelated. Muscle endurance is defined as the ability of muscle to sustain forces repeatedly or to generate forces over a period of time (Guide to physical therapy practice, 2001). The endurance time (the time that the subject can successfully contract the muscle at the assigned relative level of force) is inversely related to the relative workload (the higher the force of contraction, the lower the time of force maintenance) (Agre, 1999). At 100% of maximum force, the endurance time is usually well under 1 min although in reality, the time an individual can truly hold a maximum static muscle contraction is less than one second (Mundale, 1970). The endurance capacity of a muscle can be partly explained by the relative muscle fibre composition (Gogia and Sabbahi, 1990; Jones and Round, 1990; Watson and Trott, 1993; Uhlig et al., 1995; Mannion et al., 1998; Jull et al., 1999). Some other timedependent physiological processes as well as psychological factors could also alter the means for generating force during sustained constant-force contractions (De Luca, 1993; Gardiner, 2001; Enoka, 2002). Endurance essentially means avoiding the effects of fatigue (Jones and Round, 1990) although most times both fatigue and endurance are used interchangeably. Muscular fatigue is a loss of the ability to generate force, but such a simple definition is complicated by the fact that the extent of fatigue may vary according to the method of testing. The extent of fatigue may appear greater for voluntary contractions than for tetanic stimulation, or may differ according to whether the muscle is tested at one frequency of stimulation compared to another, or if the muscle is involved in a concentric rather than eccentric or isometric contraction. It is important therefore, in each situation to specify the type of change in muscle function and the contraction undertaken in describing “fatigue”. Although fatigue can be confused with muscle weakness and is a common general complaint in patients with a variety of clinical disorders, the term has a much more focused meaning in experimental studies. Because the physiological processes involved in performance extend from the central nervous system to the cross-bridge formation, numerous factors can contribute to the development of muscle fatigue (Enoka, 2002). These include the level of subject motivation, the neural strategy (pattern of muscle activation and motor command), the intensity and duration of the activity, the speed of a contraction, and the extent to which an activity is sustained (Enoka, 2002).
Although often tested for research purposes, endurance is rarely assessed in the clinical setting. The assessment of neck endurance/fatigue is quite complicated and the factors that contribute to their estimation require particular attention. Typically, endurance/fatigue measurements have been conducted by employing three methods, the electromyography-based method (changes occurring in the EMG signal and in the action potential velocities during a contraction), methods (usually questionnaires) that measure perceived effort during sustained contractions (subjective estimation of fatigue) and clinical tests that measure time-dependent changes (mechanical fatigue). Each of these methods has certain advantages but also serious shortcomings.
EMG methods The muscles of the cervical spine have been studied electromyographically to a much lesser extent than those of the thoracic and the lumbar spine or the limbs (Gogia and Sabbahi, 1990; Sommerich et al., 2000; Falla et al., 2002; Falla et al., 2003; Thuresson et al., 2005; Strimpakos et al., 2005a; Kallenberg et al., 2009). The lack of adequate information on cervical EMG values is due partly to the multiplicity of neck muscles, making the EMG recording a difficult task for the investigator. A comprehensive review and recommendations of surface EMG application on neck muscles has been offered by Sommerich et al. (2000) as a result of a consensus panel. Nowadays, there is no consensus among researchers regarding the reliability of neck muscle EMG measurements (Falla et al., 2002; Falla et al., 2004d; Thuresson et al., 2005; Strimpakos et al., 2005a; Kallenberg et al., 2009) although there are reports indicating that this method is able to differentiate between healthy and patients with neck pain (Falla et al., 2004c; Kallenberg et al., 2009). The plethora of parameters included in EMG studies, as well as the amount of data available from neck mobility studies, highlights the need for a separate comprehensive analysis of these variables; this approach is precluded from the objectives of this review.
Subjective estimation of fatigue An alternative method of fatigue estimation is the use of subjective scales such as the Borg scale of perceived exertion (Dedering et al., 2000; Elfving et al., 2000; Alricsson et al., 2001; Thuresson et al., 2005; Strimpakos et al., 2005a; Harrison et al., 2009). Although this method is easily applicable, the fact that different subjects may have different perceptions of effort does not permit valid extrapolation of conclusions (Strimpakos et al., 2005a). In any case, the use of subjective scales for fatigue perception can give a gross estimation of this parameter and could be utilised as an indication of subjects’ opinion for their effort.
Time-dependent methods Muscle endurance can be assessed with several time-dependent methods, statically, dynamically or isokinetically. Tests
424 that measure the time a subject can maintain a maximum static contraction or a specific relative level of maximal effort have been developed to assess the absolute or relative static endurance respectively. The dynamic endurance is assessed similarly with static endurance by measuring the number of repetitions a subject can perform a task (either requiring maximal or sub-maximal effort), usually through the full range of motion at a specific cadence. The isokinetic assessment of muscle endurance employs several tests such as: a) the 50% decrement test (the number of successful repetitions of maximum muscle contraction at a specific angular velocity until the peak torque fails to reach 50% of the initial peak torque); b) the predetermined time bout endurance test (as many maximal repetitions as possible at a predetermined angular velocity for a predetermined period of time); c) the predetermined repetitions bout endurance test (the individual performs a predetermined number of repetitions at a predetermined angular velocity and the total work performed by the muscles is the index of endurance); d) the 50-repetition decrement test (50 consecutive maximal isokinetic efforts at a predetermined angular velocity and the percent decrement of the average torque between the last three contractions and the first three contractions is used as a measure of endurance) (Agre, 1999). These tests provide a gross estimation of muscle endurance/fatigue and most of them are easily applicable in clinical settings and do not require specific or expensive instruments. On the other hand, although the measurement of the time or the number of repetitions or the work produced by the muscles provide inherently objective values, all these endurance tests are subjective in nature as they are dependent on subjects motivation to give their maximal effort or to maintain a contraction until exhaustion and indeed if MVC is not attained initially or sustained during a contraction then a false estimate of fatigue may be obtained. It is not possible to determine from reported studies how MVC was ascertained and interpreting the results from time dependant methods remains questionable. In addition, the requirement to sustain a contraction until complete fatigue may be contraindicated in many patients because of the possible risks of such an effort. Most studies evaluating neck muscle endurance have employed this method to investigate their subjects and reviews on reliability reports of these tests have been recently published (Strimpakos and Oldham, 2001; de Koning et al., 2008).
N. Strimpakos (upper cervical flexion is measured with an inflatable pressure biofeedback unit placed behind the neck, with the patient in a supine position) (Figure 3). and the conventional cervical flexion, a test that instruct the subjects to “tuck in their chins” (craniocervical flexion) and then to raise their heads from supine position. Although both tests are reliable and assess the DNF they have been developed for different purposes (de Koning et al., 2008; James and Doe, 2010). The craniocervical flexion test evaluates only the DNF while the second test (conventional flexion) assesses both superficial and deep flexor muscles. Recently, a study compared the isometric craniocervical flexion and conventional cervical flexion, did not found any significant differences between these two tests in the activation of the deep cervical flexion muscles (O’Leary et al., 2007b). However, when using these tests investigators have to be aware that the activity of superficial muscles (SCM and AS muscles) may mask impaired performance of the deep cervical flexor muscles and only the craniocervical flexion test can give specific information about deep neck flexors (Vasavada et al., 1998; Cagnie et al., 2008; Jull et al., 2008).
Whole cervical spine versus deep neck flexor endurance measurement The importance of neck flexors and especially the deep neck flexors (DNF) in patients with neck pain and headache is highlighted by many authors (Jull et al., 2004; Falla et al., 2004b; Lee et al., 2005; Falla et al., 2006; de Koning et al., 2008; Jull et al., 2008, 2009). It is proposed that the anterior cervical muscles are analogous to weak abdominal muscles in the production of low back discomfort (Krout and Anderson, 1966). Two tests in the literature have been employed in order to examine the endurance of these muscles, the craniocervical flexion test
Figure 3 The clinical application of the craniocervical flexion test. The patient is guided to each progressive pressure increment of the test by feedback from the pressure sensor. The clinician analyses the movement and detects the presence of any activity in the superficial flexors (J. Manipulative Physiol. Ther., 2008; 31:525e533, with permission from Elsevier).
The assessment of the cervical spine. Part 2
Factors influencing enduranceefatigue measurements and estimates Differences in fatigue mechanisms during maximal and sub-maximal contractions Maximal and sub-maximal contractions have different durations, involve different recruitment strategies and may as a consequence involve different fatigue mechanisms. While contractile activity of a supramaximally electrically stimulated muscle provides an objective measure of fatigue, the notion of fatigue in an exercising organism can include an increased effort necessary to maintain a sub-maximal contractile force at an unchanging level. Thus, the individual keeps exercising at the same performance level while experiencing an increase in the amount of excitation of the motor pool necessary to maintain the performance, with a simultaneous decrease in the maximal capacity of the contractile system (Gardiner, 2001). Differences in fatigue characteristics during maximal and sub-maximal contractions are partly explained by differences in motor unit recruitment, motor unit rate coding, blood flow and muscle activation patterns. These are briefly discussed in subsequent sections.
Motor unit recruitment Muscle fibre types are dictated by the motor neuron supplying them. Motor units become active at characteristic levels of force. The normal sequence of motor unit activation calls upon the smaller units first, therefore, with weak effort, the type I motor units are recruited. As the demand for higher force levels increases, the type II motor units become active (Jones and Round, 1990; Gardiner, 2001). This phenomenon is known as the “size principle of recruitment” and can be affected by several factors such as joint pain and swelling. This in turn may interfere with the abilities to perform high-intensity levels of contraction, resulting of recruitment of only type I fibres (Harris and Watkins, 1999). The recruitment pattern described above has advantages in that the most frequently used units are small, slow and fatigue resistant and can provide fine control for the majority of everyday activities such as postural adjustments which require relatively small forces. The large fast and rapidly fatigable units are only used for occasional high force contractions where fine control is not necessary (Jones and Round, 1990). During sub-maximal contractions metabolic product accumulation may decrease performance and require additional temporal and spatial recruitment of motor units in order to achieve the same force output (Blei et al., 1999). As a consequence, the increase in EMG during a fatiguing contraction held at a submaximal force is largely due to recruitment of additional motor units (Gardiner, 2001).
425 such as the quadriceps, where fine control is not generally required, force is adjusted by recruitment of motor units which, once recruited, continue firing at a fixed rate. In small muscles like those of the hand where fine control is essential, rate coding may be more important (Jones and Round, 1990). There are no available reports in literature regarding rate coding in neck muscles.
Blood flow and muscle fatigue Among the mechanisms that could contribute to fatigue is the impairment of blood flow to active muscle. An increase in muscle blood flow with motor activity is necessary for the supply of substrates, the removal of metabolites, and the dissipation of heat. When a muscle is active however, there is an increase in intramuscular pressure that compresses blood vessels and occludes blood flow when it exceeds systolic pressure. Blood flow decreases with an increase in the level of the sustained force but only for tasks that involve more than 15% of the MVC force (Enoka, 2002). This is more pronounced during isometric contractions because the blood flow within the muscle is maintained during the dynamic contraction by enhanced venous return from the contracting muscle (Masuda et al., 1999). It would not be appropriate therefore to compare the extent of fatigue between different types of contraction as the mechanisms of fatigue will differ between them depending on the extent of blood flow.
Muscle activation patterns and fatigue A resultant muscle force about a joint can be achieved by a variety of muscle activation patterns. This flexibility certainly exists amongst groups of synergist muscles such as the cervical spine muscles (Tamaki et al., 1998; Semmler et al., 1999). Because of this possibility, one option the motor system has for delaying the onset of force decline (fatigue) is to vary the contribution of synergist muscles to the resultant muscle force enabling different muscles to rest and therefore prevent fatigue. This is a complementary muscle recruitment strategy of the body in order to maintain a constant force. Although this possibility is available only when the task requires sub-maximal forces (Enoka, 2002), it applies to most activities of daily living that involve such forces. Especially in cervical spine, we have to keep this principle in mind since during endurance assessment patients could differentiate their patterns activating more the strongest superficial muscles in contrast to weaker deep neck muscles resulting thus in wrong estimation of this parameter. Low load tests and supervision for performing the right movement patterns during assessment may be used in order to overcome this limitation.
Implications for clinicians and researchers regarding neck endurance/fatigue assessment
Rate coding An alternative way of modulating force is to vary the frequency of stimulation. This is known as rate coding. It is not known to what extent the two methods of varying force, recruitment and rate coding are used during a normal voluntary contraction. It is possible that in large muscles
Neck muscle endurance and fatigue can be assessed by using either clinical methods (time dependent and subjective) or more sophisticated (EMG-based) methods. Moreover the assessment of fatigue could involve the whole cervical spine or only its upper part. Many authors have suggested that the lower endurance of deep neck flexors seems to be important
426 factor for the development of neck pain and headache. Regarding the clinical assessment of endurance, some precautions have to be taken to ensure valid results. Low load tests are essential for assessing the deep neck muscles’ endurance together with isometric evaluation since the main function of small neck muscles is the stabilisation of cervical structures. Sometimes, clinical tests performed until exhaustion are not preferable, especially in acute situations. Tests that use incremental levels of effort (i.e. subject aims to sustain a nominated pressure for as long as possible) could be employed in these situations. Furthermore, the position of the subjects (sitting, standing or lying) can change the resulting values since the load in each test may be different. Test position has to be kept constant between measurements and torso stabilisation could help in this way. Aforementioned issues for strength assessment such as warm-up, diurnal variations, hormonal influences, etc could also be applied for endurance measurements. Finally, investigators must be aware that muscle activation patterns could be changed during assessment as a result of fatigue making more prominent the superficial neck muscles resulting in invalid estimates and conclusions.
Conclusion Physical factors such as strength and endurance/fatigue have been considered as significant parameters for the normal function of the cervical spine along with neck ROM and proprioception (presented in a previous paper). The presence of physical impairments in the neck may lead to the development of chronic neck pain and headache. However, the complicated nature of the cervical spine requires the awareness of the multiple factors a clinician or researcher has to take into account throughout their evaluation. For these reasons presently there is no consensus among clinicians and researchers for the best method and protocol for assessing neck strength and endurance. The best way to obtain reliable and valid values is to keep a constant assessment procedure in all measurements, to isolate as much as possible the cervical spine from the rest of the body by using stabilisation frames, to test the reliability of all instruments being used, and to motivate subjects to give their best efforts. Issues such as warm-up and familiarisation sessions before measurements, diurnal variations and hormonal influences, are all essential for reliable and valid results in both neck strength and endurance/fatigue assessments. Low load tasks with close monitoring of muscle activation patterns are also important components in cervical spine endurance assessments.
Text box Neck strength and endurance/fatigue evaluation have been used extensively in clinical research and practice. Their assessment however, is compromised by many factors concerning either the cervical spine as a structure or the strength and endurance variables themselves. It is important for obtaining valid and reliable values to maintain consistent assessment procedures in all sessions, to isolate the cervical spine
N. Strimpakos
movement from the rest of the body, to ensure maximum efforts from the subjects by motivating them, and also to assess at the same time-of-day after undertaking a warm-up and familiarisation session. It is also essential to use low load tests to evaluate the endurance of small neck muscles (especially the deep neck flexors) and to supervise closely the test in order to ensure the proper performance and to avoid compensation from other muscles.
Acknowledgements I would like to thank my colleague Dr. M.J. Callaghan for reviewing the manuscript
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Journal of Bodywork & Movement Therapies (2011) 15, 431e435
available at www.sciencedirect.com
journal homepage: www.elsevier.com/jbmt
CLINICAL METHODS
Effectiveness of direct vs indirect technique myofascial release in the management of tensiontype headache M.S. Ajimsha, MPT (Neuro), ADMFT, PhD (Physiotherapy) a,b,* a b
Myofascial Therapy and Research Foundation, India School of Physiotherapy, AIMST University, 08100 Bedong, Kedah, Malaysia
Received 27 July 2010; received in revised form 18 January 2011; accepted 18 January 2011
KEYWORDS Myofascial release; Myofascial trigger points; Tension headache
Summary Background: Tension-type headache (TTH) is essentially defined as bilateral headache of a pressing or tightening quality without a known medical cause. Myofascial release (MFR) is currently being applied for patients with TTH but its efficacy has not been evaluated formally. Objective: To investigate whether direct technique myofascial release (DT-MFR) reduces the frequency of headache more effectively than the indirect technique myofascial release (IDTMFR) in comparison to a Control Group receiving slow soft stroking. Design: Randomized, controlled, single blinded trial. Setting: The clinical wing of Myofascial Therapy and Research Foundation, Kerala, India. Participants: 63 patients with episodic or chronic tension-type headache. Interventions: DT-MFR, IDT-MFR or Control. The techniques were administered by certified myofascial release practitioners and consisted of 24 sessions per patient over 12 weeks. Main outcome measure: Difference in numbers of days with headache between Weeks 1e4 (i.e. 4 weeks prior to start of Intervention) and Weeks 17e20, following 12 weeks of Intervention between Weeks 5e16 as recorded by participants in headache diaries. Results: The number of days with headache per 4 weeks decreased by 7.1 (2.6) [mean (SD)] days in the DT-MFR group compared with 6.7 (1.8) days in the IDT-MFR group and 1.6 (0.5) days in the control group, (P < 0.001). Patients in the DT-MFR Group, IDT-MFR Group and Control Group reported a 59.2%, 54% and 13.3% reduction in their headache frequency in Weeks 17e20 compared to that in Weeks 1e4. Conclusions: This study provides evidence that Direct Technique or Indirect Technique Myofascial Release is more effective than the Control Intervention for tension headache. ª 2011 Elsevier Ltd. All rights reserved.
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432
Introduction Tension-type headache (TTH) is essentially defined as bilateral headache of a pressing or tightening quality without a known medical cause. Tension-type headache is classified as episodic if it occurs on less than 15 days a month and as chronic if it occurs more often (IHS, 1997). A survey from the United States found a one-year prevalence of 38% for episodic tension-type headache and 2% for chronic tension-type headache (Schwartz et al., 1998). Present pain models for tension-type headache suggest that nociceptive inputs from peripheral tender muscles can lead to central sensitization in chronic tension-type headache (De-Las-Pen ˜as et al., 2007). Myofascial Trigger Points are highly prevalent in patients with tension-type headache (Couppe ´ et al., 2007). Myofascial Release (MFR) is the application of a low load, long duration stretch into the myofascial complex, intended to restore the optimal length of this complex, decrease pain and improve function (Barnes, 1990). It has been hypothesized that fascial restrictions in one part of the body cause undue tension in other parts of the body, due to fascial continuity; in turn, this may create stress on any structures that are enveloped, divided, or supported by fascia (Schleip et al, 2003). Myofascial practitioners believe that by restoring the length and health of restricted connective tissue, pressure can be relieved on pain sensitive structures such as nerves and blood vessels. Myofascial release generally involves slow, sustained pressure (120e300 s) applied to restricted fascial layers either directly (DT-MFR) or indirectly (IDT-MFR). The rationale for these techniques can be traced to various studies that looked at the plastic, viscoelastic and piezoelectric properties of connective tissue (Schleip, 2003; Greenman, 2003; Pischinger, 1991). Myofascial Release is being used to treat patients with TTH (Baldry, 2005; Stanborough, 2004; Richter and Hebgen, 2009), but there are few formal reports of its efficacy. At the Myofascial Therapy and Research Foundation in Kottayam, Kerala, India, both the Direct Technique Myofascial Release (DT-MFR, as promoted by Stanborough, 2004) and Indirect Technique Myofascial Release (IDT-MFR, as promoted by Manheim, 2001) are used. DT-MFR is thought to work directly on restricted fascia; practitioners use knuckles or elbow or other tools to slowly sink into the fascia, and the pressure applied is a few kilograms of force to contact the restricted fascia, apply tension, or stretch the fascia. IDTMFR involves application of gentle stretch e the pressure applied is a few grams of force, and the hands tend to follow the direction of fascial restriction, hold the stretch, and allow the fascia to ‘unwind’ itself. The primary objective of the present study was to evaluate the efficacy of DT-MFR and IDT-MFR in the management of TTH, treating fascia in the head, neck and face in accordance with the fascial meridians proposed by Myers (2003). It was not the intent of this study to compare which among DT-MFR and IDT-MFR is more effective for the management of tension-type headache.
Methods This study was carried out in the clinical wing of MFTRF, Kottayam, Kerala, India. Individuals aged 18e50 years with
M.S. Ajimsha a diagnosis of episodic or chronic TTH lasting at least 12 months, and who had completed a 4-week baseline headache diary were eligible for inclusion in the study. Those with a history of additional migraine headache, secondary headaches, age >50 years, use of analgesics on more than 10 days a month, prophylactic headache treatment with drugs in the 4 weeks prior to randomization, and any other treatment for TTH during the previous 12 months were excluded. The study protocol was approved by the Ethics Committee of MFTRF. Between July 2008 and February 2009, 76 patients were referred to MFTRF, India, with a diagnosis of TTH. Of this, 63 individuals who met the Inclusion Criteria and provided written informed consent were randomized to DT-MFR, IDT-MFR, or Control using a 2:2:1 list (as done in studies by Tully et al, 2007; Sherman et al, 2010). Participants were not blinded to the intervention they were randomized to. Two evaluators blinded to the group to which the participants belonged analyzed headache diaries.
Interventions All 3 interventions were provided twice weekly for 12 weeks (Weeks 5e16); the duration of each treatment session was 1 h.
DT-MFR technique The technique used was same for all the patients in DT-MFR (Stanborough, 2004). All techniques were performed bilaterally, 3 min on each side. The Protocol was as follows: I. Upper Trapezius release II. Lateral/anterior cervical techniques. a) Using soft fist to treat the fascia at the mastoid process. b) Using the first three metacarpophalangeal joints to treat the submastoid and occipital soft tissue. III. Deep posterior myofasciae. a) Release of nuchal ligament. b) Melting into the deep small muscles of the posterior neck. c) Release of the deep neck flexor muscles. IV. Release of cranial base and suboccipital myofascia. V. Decompression of the occipital condyles. VI. Release of the temporalis fascia. VII. Release of the epicranial aponeurosis.
IDT-MFR technique The technique used was same for all the patients in IDT-MFR (Manheim, 2001). Steps V and VI were performed bilaterally for 5 min on each side. The Protocol was as follows: I. Gross stretch of the posterior cervical musculature (10 min). II. Cranial base release (10 min). III. Hair pull (10 min). IV. Ear pull (10 min).
Effectiveness of direct vs indirect technique myofascial release V. Stretch of face muscles (10 min). VI. Gross stretch of the Sternocleidomastoid (10 min).
Control intervention Patients in the Control Group received slow soft stroking with finger pads all over the head in the same areas as the application of Myofascial Release (in the other Groups) for the same duration (1 h per treatment session), twice a week for 12 weeks. After the completion of the study, patients in the Control arm were provided MFR therapy, as advised by the Ethics Committee. Patients in all groups filled in headache diaries the month before randomization (Weeks 1e4), and following treatment (Weeks 9e20). All study participants were advised to take medication for headache exacerbations as required, but were required to record them in their headache diaries. Practitioners who provided MFR therapy in this study had been trained in the techniques for at least 100 h and had a median experience of 10 months with the technique. The DT-MFR, IDT-MFR, and Control Treatments consisted of 24 sessions, each lasting an hour, given over 12 weeks in 2 sessions per week with a minimum of 2 days gap between sessions. The primary outcome measure was the difference in number of days with headache between Weeks 1e4 and Weeks 17e20.
Statistics The three groups at baseline were compared using one-way analysis of variance. Then, in accordance with the primary objective of the study, we compared the number of days with headache in the DT-MFR and IDT-MFR groups as compared to Control Group using unpaired t-test. A two-tailed P value less than 0.05 was accepted as statistically significant.
Results Of the 63 individuals recruited into this study, 56 participants (22 in DT-MFR Group; 22 in IDT-MFR Group and 12 in Control Group) completed the study protocol. Two participants in the DT-MFR and one participant each from the remaining 2 Groups dropped out of the study without providing any specific reason for it. One participant in the
Table 1
433
DT-MFR and two participants in the IDT-MFR groups did not maintain headache diaries as advised and their data were excluded from the results presented below. Within the study period, no serious adverse events occurred in any of three Groups. Three patients from the DT-MFR group and one from the IDT-MFR group reported headaches in the first week following initiation of treatment, and this was reported to have subsided within a week without any medication. There were no statistically significant differences between the groups for any of the baseline characteristics (Table 1). From Weeks 1e4 to Weeks 17e20, the number of days with headache per 4 weeks decreased by 7.1 (SD 2.6) days in the DT-MFR group compared with 6.7 (SD 1.8) days in the IDT-MFR group and 1.6 (SD 0.5) days in the Control Group (difference: DT-MFR vs IDT-MFR, 0.6 days, 95% confidence interval 2.4 to 1.2 days, P Z 0.51; DT-MFR vs Control Group, 5.8 days, 7.6 to 4.0 days, P < 0.001, IDT-MFR vs Control Group, 5.4 days, 7.2 to 3.7 days, P < 0.001) (Table 2). The proportion of responders, defined as participants who had at least 50% reduction in headache days between Weeks 1e4 and Weeks 17e20, was 81.8% in the DT-MFR Group, 86.4% in the IDT-MFR Group, and 0% in the Control Group. Patients in the DT-MFR group reported a 59.2% reduction in their headache frequency; IDT-MFR group reported 54% reduction whereas Control Group reported 13.3% reduction in their pain frequency per 4 weeks in the Weeks 17e20. However, differences in headache frequency between the DT-MFR and the IDT-MFR Groups were statistically insignificant.
Discussion The principal finding of this ‘proof of the concept’ study is that both of the Myofascial Release interventions tested in this study were significantly more effective than slow stroking for decreasing the frequency of tension-type headache. The principal difference between the Direct and Indirect Techniques of Myofascial Release used in this study is that the pressure applied was of the order of kilograms and for a shorter duration in the Direct Technique, whereas in the Indirect Technique the amount of pressure is of the order of a few grams but sustained longer. One limitation of this trial was that practitioners could not be blinded. Another limitation was the absence of long-term follow up
Baseline characteristics of study participants (n Z 56).
Characteristic
All Patients (n Z 56)
DT-MFR (n Z 22)
IDT-MFR (n Z 22)
Control Group (n Z 12)
Males:Females Age (Years) Body Mass Index (Kg/m2) Episodic Tension-Type Headache Chronic Tension-Type Headache Duration of Condition (Years), as seen from physicians reports Frequency of Headache in Weeks 1e4 (Baseline)
20:36 43.8 (5.4) 24.6 (5.7) 47 (83.9) 9 (16.1) 7.4 (7.7)
7:15 43.7 24.7 20 2 7.1
8:14 44.7 24.8 18 4 7.3
5:7 43.0 24.2 9 3 7.7
12.1 (2.7)
(5.6) (5.9) (90.9) (9.1) (7.2)
12 (2.8)
(5.2) (6.2) (81.8) (18.2) (8.1)
12.4 (2.8)
(5.4) (5.0) (75) (25) (7.7)
12 (2.5)
Data are the mean (SD) except for Gender and TTH, which are expressed as ratio and number (Percentage) respectively.
434 Table 2
M.S. Ajimsha Headache diary readings (17e20 weeks) following completion of 3 months Intervention. Data are the means (SD).
Headache Diary Reading
DT-MFR
IDT-MFR
Control Group
Headache Frequency (Weeks 1e4) Frequency of Headache (Weeks 17e20) Mean (SD) of difference in days with headache between Weeks 1e4 and Weeks 17e20 Comparison of headache frequency scores of the DT-MFR, IDT-MFR and the Control Groups of the Weeks 17e20. (95% Confidence Interval) P value by unpaired t-test
12 (2.8) 4.9 (1.7) 7.1 (2.6)
12.4 (2.8) 5.7 (1.3) 6.7 (1.8)
12 (2.5) 10.4 (2.7) 1.6 (0.5)
DT-MFR vs IDT-MFR 0.6 (2.4 to 1.2)
DT-MFR vs Control group 5.8 (7.6 to 4.0)
IDT-MFR vs Control Group 5.4 (7.2 to 3.7)
0.51
<0.001
<0.001
of study participants. A slight improvement over time occurred in the Control Group; this could be due to a “meaning response” (Moerman and Jonas, 2002). Myofascial Release has been reported to reduce pain and improve quality of life in idiopathic scoliosis (LeBauer et al., 2008), Raynaud’s phenomenon (Walton, 2008) and in systemic sclerosis (Martin, 2009). A recent study has shown that treatment with Myofascial Release following repetitive strain injury resulted in normalization in apoptotic rate, cell morphology changes, and reorientation of fibroblasts (Meltzer et al., 2010). Active myofascial trigger points in the cervical and suboccipital musculature have been identified in 65% of individuals with chronic tension-type headache (DeLas-Penas et al., 2006; Couppe et al., 2007). According to Schleip (2003), under normal conditions, fascia tends to move with minimal restrictions. However, injuries resulting from physical trauma, repetitive strain injury, and inflammation are thought to decrease fascia tissue length and elasticity resulting in fascial restriction. It is possible that pain relief due to myofascial release is secondary to returning the fascial tissue to its normal length. Shah et al. (2008) have experimentally assessed the biochemical milieu of active trigger points and have characterized them as consisting of a higher than normal concentration of inflammatory mediators. It is also possible that myofascial release leads to blood flow changes that allow the inflammatory mediators to be removed away from trigger points; this is a hypothesis that merits investigation.
Conclusions Both the Direct and Indirect Techniques of Myofascial Release investigated in this trial were more effective than a Control Intervention consisting of slow soft stroking with finger pads for the treatment of tension-type headache. A significant proportion of patients with TTH might benefit from the use of Myofascial Release. The mechanisms underlying these responses merit investigation.
Funding sources and conflicts of interest This study was funded by the Myofascial Therapy and Research Foundation, India. No authors declare any conflict of interest, financial or otherwise. MFTRF India is a registered Non Governmental Organization, formed with the aim of conducting education, research and awareness programs in the field of soft tissue
manipulations and delivering quality hands on care for those in need.
Acknowledgment We thank all the practitioners and professionals of MFTRF, India and the physicians who participated in the consensus process and analysis to establish the trial interventions. We are expressing our special gratitude to Dr. E. S. Prakash, Associate Professor, School of Medicine, AIMST University, Malaysia for his expertise editing of the manuscript.
References Baldry, P., 2005. Pain in the Head and Face, Tension Type Head Ache, Acupuncture, Trigger Points and Musculoskeletal Pain, third ed.. Elsevier Ltd, pp. 251e270. Barnes, J.F., 1990. Myofascial Release: The Search for Excellence. Rehabilitative Services, Paoli, Pa. Couppe ´, C., Torelli, P., Fuglsang-Frederiksen, A., Andersen, K.V., January 2007. Myofascial trigger points are very prevalent in patients with chronic tension-type headache: a double-blinded controlled study. The Clinical Journal of Pain 472, 23e27. Ferna ´ndez-De-Las-Pen ˜as, C., Cuadrado, M.L., Arendt-Nielsen, L., Simons, D.G., Pareja, J.A., 2007 May. Myofascial trigger points and sensitization: an updated pain model for tension-type headache. Cephalalgia 27 (5), 383e393. Ferna ´ndez-De-Las-Pen ˜as, C., Alonso-Blanco, C., Cuadrado, M.L., Gerwin, R.D., Pareja, J.A., March 2006. Trigger points in the suboccipital muscles and forward head posture in tension-type headache. Headache 46 (Issue 3), 454e460. Greenman, P., 2003. Principles of Manual Medicine. Lippincott, Williams & Wilkins, Philadelphia, pp. 155e158. International Headache Society, 1997. ICC-10 guide for headaches. Cephalalgia 17 (Suppl. 19), 1e82. LeBauer, A., Brtalik, R., Stowe, K., 2008. The effect of myofascial release (MFR) on an adult with idiopathic scoliosis. Journal of Bodywork and Movement Therapies 12, 356e363. Manheim, C., 2001. Cervical Region, the Myofascial Release Manual, third ed.. SLACK, Incorporated, pp. 98e113. Meltzer, K., Thanh, M., Cao, V., et al., 2010. In vitro modeling of repetitive motion injury and myofascial release. Journal of Bodywork and Movement Therapies 14, 162e171. Martin, M.M.P., 2009. Effects of the myofascial release in diffuse systemic sclerosis. Journal of Bodywork and Movement Therapies 13, 320e327. Moerman, D.E., Jonas, W.B., 2002. Deconstructing the placebo effect and finding the meaning response. Annals of Internal Medicine 136, 471e476.
Effectiveness of direct vs indirect technique myofascial release Myers, T.W., 2003. Anatomy Trains: Myofascial Meridians for Manual and Movement Therapists. Churchill Livingstoneª, pp. 17e20. Pischinger, A., 1991. Matrix and Matrix Regulation: Basis for a Holistic Theory in Medicine. Haug International, Brussels. Richter, P., Hebgen, E., 2009. Muscles of Head and Neck Pain, Trigger Points and Muscle Chains in Osteopathy. Thieme, pp. 125e144. Schleip, R., 2003. Fascial plasticity e a new neurobiological explanation. Journal of Bodywork and Movement Therapies 7 (1), 11e19, and 7(2): pp. 104e116. Schwartz, B.S., Stewart, W.F., Simon, D., Lipton, R.B., 1998. Epidemiology of tension-type headache. Journal of American Medical Association 279, 381e383. Shah, J.P., Danoff, J.V., Desai, M.J., Parikh, S., Nakamura, L.Y., Phillips, T.M., et al., 2008. Biochemicals associated with pain and inflammation are elevated in sites near to and remote from
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active myofascial trigger points. Archives of Physical Medicine and Rehabilitation 89, 16e23. Sherman, K., Cherkin, D., Cook, A., et al., 2010. Comparison of yoga versus stretching for chronic low back pain: protocol for the Yoga Exercise Self-care (YES) trial. Trials 11, 36. Stanborough, M., 2004. Towards the More Effective Treatment of Headaches, Direct Release Myofascial Technique, first ed.. Elsevier Limited. Tully, M., Cupples, M., et al., 2007. Randomised controlled trial of home-based walking programmes at and below current recommended levels of exercise in sedentary adults. Journal of Epidemiol Community Health 61 (9), 778e783. Walton, A., 2008. Efficacy of myofascial release techniques in the treatment of primary Raynaud’s phenomenon. Journal of Bodywork and Movement Therapies 12, 274e280.
Journal of Bodywork & Movement Therapies (2011) 15, 436e445
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REVIEW
The use of abdominal massage to treat chronic constipation Marybetts Sinclair, LMT* c/o Maren, PO Box 582 Philomath, OR 97370, USA Received 26 August 2009; received in revised form 28 June 2010; accepted 19 July 2010
KEYWORDS Bowel stasis; Peristalsis; Ileus; Self-massage; Transit-time
Summary Constipation is a disorder of gastrointestinal motility characterized by difficult or decreased bowel movements, and is a common condition in Western countries. Laxatives are the most common strategy for managing constipation. However, long-term use of some laxatives may be associated with harmful side-effects including increased constipation and fecal impaction. Abdominal massage, once an accepted method of treating constipation, is no longer standard of care, but may be a desirable therapy for this condition because it is inexpensive, non-invasive, free of harmful side-effects, and can be performed by patients themselves. However, until recently, evidence for its effectiveness was not strong enough to make a recommendation for its use in constipated patients. In 1999, Ernst reviewed all available controlled clinical trials, and found that there was no sound evidence for the effectiveness of abdominal massage in the treatment of chronic constipation. This article reviews scientific evidence from 1999 to the present, regarding abdominal massage as an intervention for chronic constipation. Since that time, studies have demonstrated that abdominal massage can stimulate peristalsis, decrease colonic transit time, increase the frequency of bowel movements in constipated patients, and decrease the feelings of discomfort and pain that accompany it. There is also good evidence that massage can stimulate peristalsis in patients with post-surgical ileus. Individual case reports show that massage has been effective for patients with constipation due to a variety of diagnosed physiologic abnormalities, as well as in patients with long-term functional constipation. ª 2010 Elsevier Ltd. All rights reserved.
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Use of abdominal massage to treat chronic constipation
Introduction Constipation is a disorder of gastrointestinal motility characterized by difficult or decreased bowel movements (less than three times a week). When the digestive system is functioning optimally, food is eaten and digested, and then the residue is excreted, usually within 20e56 h (see Figures 1 and 2) (Liu et al.,, 2005; Southwell et al., 2009) Constipation may be brought on by a change in diet, medication, a change in daily routine, abdominal surgery or acute emotional stress. Longer-lasting constipation, however, generally occurs when disease, poor diet, muscle spasticity, physical obstructions, sluggish contractions, or other factors cause stool to move through the colon at a slower-
437 than-normal pace, until by the time it reaches the end of the large intestine it has lost a great deal of water and has become hard, dry, and difficult to eliminate (Leung, 2007; Locke et al., 2000). Constipation affects about 9% of children, and between 12 and 19 percent of all adults. (Shan et al., 2008; Van de Berg et al., 2006; Wald et al., 2008). In the United Kingdom 10% of the general population, 20% of elderly living at home, 49% of those in long-term care, and 70% of persons with learning disabilities have chronic constipation. English citizens spend 67 million pounds on laxatives each year (Johanson et al., 2007; Emly and Rochester, 2006; Addison et al., 2003). In the United States and Canada, chronic constipation affects
Figure 1 “Structures of the Digestive System”, reprinted with permission from Stedman’s Medical Dictionary, 27th edition, Baltimore: Lippincott, Williams and Wilkins, 2000.
438
Figure 2 “Retained Feces in Colon of Patient with Functional Constipation”, reprinted with permission from Federle, M., Diagnostic Imaging Abdomen, AMIRSYS Inc., Salt Lake City Utah, 2007.
about 15% of the population, and American citizens spend 725 million dollars on laxatives each year (Higgins, 2004; Shan et al., 2008). In a survey of 13,879 adults from 7 countries, an average of 12.3% of adults were constipated, with a higher percentage occurring in women and seniors (Wald, 2008). Women are especially likely to become chronically constipated (Rao, 2008, 2009, Davies et al., 2009; Higgins, 2004; Talley, 2004; Van de Berg et al., 2006; Wald, 2008; Johnson, 1989). Even those who have a bowel movement every day may have hidden constipation, that is, feces remaining in any of the three divisions of the colon or in the rectum itself (Raahave et al., 2004). Current allopathic treatment of constipation includes dietary changes (especially an increase in the consumption of fiber and water), attention to habits/urge to defecate, physical exercise, enemas, bulk-forming, osmotic or stimulant laxatives, and stool softeners. Biofeedback training may be used for patients with constipation caused by poor rectoanal coordination (Rao, 2008). Surgical treatment may be used as a last resort. Naturopathic medicine views constipation as having one of three primary causes, atonic (due to dilated or ptosed intestines, loose rectal muscles, or inactivity), spastic (due to irritation caused by food, medicines, parasites or emotional stress) or obstructive (due to adhesions from surgery or infection). Treatment includes nutrition (including dietary changes, probiotics, digestive enzymes and dietary supplements), internal and external hydrotherapy, botanical and homeopathic medicines and manual therapies such as massage and visceral manipulation (Mariotti, 2009). Colon hydrotherapy may be employed as a method of stretching the muscles and fascia of the colon from within (Dorman, 2006).
M. Sinclair From the late 1800’s through the 1950’s, in both Europe and the United States, Swedish massage, using petrissage, effleurage, vibration and tapotement strokes applied to the anterior abdominal wall, was a widely used treatment for constipation (Kleen, 1921; Kellogg, 1923; Starr, 1903; Whorton, 2000) (Oriental styles of bodywork have long used abdominal techniques to reduce constipation) (Chia, 1991; Matsumoto and Birch, 1998; Marin, 1999). Practitioners believed that by applying pressure to the anterior abdominal wall, they were compressing the digestive organs between the massaging fingers and the posterior wall of the abdominal cavity and stimulating peristalsis. Some, but not all, believed massage also propelled feces through the intestines towards the rectum (Kellogg, 1923). Some practitioners targeted massage to the large intestine so specifically, that one prominent physician recommended the abdomen of the constipated patient be X-Rayed prior to massage to identify the colon’s exact location (Kellogg, 1923). Abdominal massage may have inadvertently treated scar tissue or trigger points in the muscles of the midabdomen, either of which can cause excess gas and sensations of abdominal swelling and fullness, and some patients may have confused relief of their symptoms with a reduction in constipation (Travell et al., 1999). Professionals in the field of massage therapy continue to recommend abdominal massage for constipation (Fernandez, 2006; Sinclair, 2004).
Literature search Observational studies and case reports comprise most of the evidence for the effectiveness of abdominal massage as a treatment for constipation. In 1999, a systematic review of evidence by Ernst examined observational studies, case reports and four controlled clinical trials. Ernst concluded that all four clinical trials had methodological flaws. Only one was randomized, and one trial consisted of only one patient. In addition, they were not consistent in terms of the trial design, the type of massage that was given, or the type of patients that were in the trials. Therefore, he found that there was no sound scientific evidence regarding the effectiveness of abdominal massage in the treatment of chronic constipation. Looked at collectively, however, the trials showed enough positive results, such as decreased constipation and improved patient well-being, that more rigorous trials e randomized, controlled, and with larger numbers of patients e were warranted (Ernst, 1999). Since the appearance of Ernst’s paper, there have been further observational studies with specific populations: two with spinal cord injured patients (Albers et al., 2006; Ayas et al., 2006) and one each with groups of post-stroke patients (Jeon and Jung, 2005), elderly patients (Kim et al., 2005), hospice patients (Preece, 2002) and profoundly disabled group-home residents (Emly, 2001). In each case, abdominal massage decreased constipation and associated abdominal discomfort. For example, Ayas et al found that 15 min of abdominal massage per day decreased colonic transit time, abdominal distention, and fecal incontinence, and increased frequency of defecation in 24 spinal cord injured patients (Ayas et al., 2006). Emly’s
Use of abdominal massage to treat chronic constipation study took place at a group home for profoundly disabled adults, all of whom had been taking laxatives for extended periods of time. At the beginning of the study, all laxatives were withdrawn and daily abdominal massage using moderate-pressure effleurage, kneading and vibration was given instead. Subjects were assessed after eighteen months and not only were they no more constipated than when using laxatives, in some cases there was marked improvement in digestive function (Emly, 2001). Four individual case reports have also appeared since 1999, where abdominal massage effectively decreased constipation. These individuals were a 64 year-old woman with myelopathy (HAM/TSP, a spinal cord inflammation with effects similar to those of a traumatic spinal cord injury), an 8-year-old boy with lifelong constipation, a severely constipated female patient in her mid-eighties with abdominal muscle weakness, and a 31-year-old male in the acute phase of Guillan-Barre syndrome (Liu et al., 2005; Quist, 2007; Harrington and Haskvitz, 2006, and Shirreffs, 2001) (footnote: Acute Guillain-Barre presents with polyneuritis, which leads to weakness of the muscles of the digestive tract, sluggish contractions and constipation). There were many variations in the observational studies and case reports, such as the specific massage technique, how it was applied, and for how long. None were randomized, controlled trials. In 2009 Lamas carried out a randomized, controlled trial on the use of abdominal massage with sixty elderly patients. All subjects had functional constipation which had been treated with laxatives for several years. Patients were divided into a control and an intervention group, both of which continued to take laxatives during the study period. The intervention group received 32 massages over a period of 8 weeks. Each session began with 8 min of hand massage to help patients relax, followed by 7 min of abdominal massage. The massage technique was based upon the Tactile Stimulation Method of Birkestad which consists primarily of palm-to-skin stroking, gentle pressing, and static touch, all using very light pressure (Birkestad, 1999). For Lamas’ study, it consisted of light-pressure longitudinal and transverse strokes over the abdomen, and clockwise circular movements over the presumed course of the colon. Using a gastrointestinal function questionnaire, subjects were assessed before the study began, after the fourth week, and then after the eighth week, the end of the study. No significant differences were found after 4 weeks. At 8 weeks, however, the massage group had significantly less constipation, less abdominal pain, and more bowel movements than the control group. Researchers also found that the more constipated the patients were at the beginning of the study, the greater the improvement in their symptoms (Lamas et al., 2009). Another randomized controlled study investigated the effectiveness of mechanical abdominal “massage” upon the peristalsis of patients who had had colon surgery one day before. Peristalsis normally slows or stops altogether after colon surgery, but use of a machine which applied intermittent pressure to the abdomen significantly decreased the time to first passage of flatus after surgery for the mechanical massage group versus a control group (Le BlancLouvry et al., 2002).
439
Anatomy and pathophysiology The abdominal viscera lie directly beneath the muscles of the anterior abdominal wall. Longitudinal and circularly arranged smooth muscle, with sensory neurons and nerve endings lying within it, make up the walls of the stomach, small intestine and colon. The vagus nerve innervates most of the digestive tract, and parts not innervated by the vagus are innervated by pelvic nerves from the sacral region of the spinal cord. The vagus can be impinged as it passes through the jugular foramen or at the cranial base, possibly affecting visceral function (Joyce and Clark, 1996). There may be trigger points in the intestinal muscles themselves: when stimulated with an inflatable balloon trigger areas in the esophagus, small intestine and colon can reproduce patients’ abdominal pain (Moriarty and Dawson, 1982; Travell et al., 1999). It is unknown if there is a relationship between these trigger points and constipation. Digestion is a complex process requiring the co-ordinated interaction of mechanical, chemical, neurological and hormonal elements. Except at the mouth and anus, digestion is performed entirely by smooth muscles, whose actions include churning, kneading and propulsion of chyme, reflex emptying of the colon (the gastrocolic reflex), and rectal compliance. Efficient movement of contents through the system has a great deal to do with the sensory neurons and nerve endings that sense distortion, pinching, contraction and distention of the gut wall. When a segment of smooth muscle is distended with approximately 2 mm Hg of pressure, stretch receptors of the afferent neurons located in the lumen wall are activated and contraction occurs of both longitudinal and circular muscles. The circular muscles create a ring around the lumen. At the same time, a few centimeters above the higher pressure area, intestinal wall muscles contract, while below the point of stimulus, the muscles relax. Thus pressure is created on chyme, pushing it forward and bulging or stretching the next segment of intestinal wall muscle in turn, which stimulates yet another contraction and creates a peristaltic wave. Most contractions involve only 1e4 cm of bowel before they die out, thus peristaltic contractions move the contents of the intestines along at about 1 cm per minute. Not only large amounts of chyme, but lumps of food, artificial objects, intestinal parasites and tension in the muscles themselves can stimulate contractions, while very small stools (typical of patients on low-fiber diets) fail to distend the lumen sufficiently to stimulate peristalsis. Artificial distention or stimulation of the intestinal walls by enemas, digital stimulation, medical procedures and temperature extremes can also stimulate muscle contractions (Lippincott’s, 2008; King et al., 1986). In anesthesized dogs, gentle stroking or touching of the mucosal (or inner) surface of the small intestines stimulated contractions which lasted 30 s to 1 min (Neya, 1993). Mechanical stretch of segments of isolated guinea pig intestine causes a contraction of the intestinal muscle (Brookes et al., 2004). When the intestinal wall just proximal to a sphincter becomes distended, the sphincter relaxes briefly, during which time chyme is propelled through it. Simultaneously,
440 the muscles just distal to the chyme relax: chyme is thus moved forward, while sphincters contract again to prevent backflow. In the colon, muscle contractions squeeze, compact and propel chyme, squeezing out water in the process and forming the remaining paste into stool. Slow transit of stool may occur at any point throughout the colon, and in only one or two segments rather than all three (van der Sijp et al., 1993). Spasm of colonic muscles may occur with some illnesses such as pneumonia or myocardial infarction (Barral, 2005) Most of the actual propulsion of stool happens when mass movements (large waves of peristaltic action) occur, 1e4 times daily, generally just after eating a meal (see Figure 3). At this time, a massive contraction of the cecum and colon, creating pressures as
M. Sinclair high as 100 mg Hg, moves part of the contents in the cecum up the ascending colon, into the transverse colon and then down into the descending colon and rectum. The contraction lasts 1e4 min before it decreases and then finally stops altogether. Finally, more contractions move the now-formed stool into the rectum (These muscle contractions can empty the bowel as high up as the splenic flexure). The peristaltic action of the sigmoid colon and distention of its distal end stimulate contraction of the large muscles of the rectum, thereby increasing rectal pressure and stimulating relaxation of the internal and external sphincters. Abdominal wall muscles, which normally are voluntarily contracted to increase intra-abdominal pressure during a bowel movement, also enhance defecation by applying inward and downward pressure on
Text box 1. Factors that interfere with the timely movement of abdominal contents through the digestive system More than one factor may be present in the same patient. ))) Lifestyle-related factors such as a diet that is low in fiber, regularly ignoring the urge to defecate, and chronic dehydration (Older people may drink less in an attempt to control incontinence). Another factor, low muscle tone due to inactivity, slows gastrointestinal transit time (Cordain, 1986; Oettle, 1991; Peters et al., 2001; Petticrew et al., 2001; Davies et al., 2009; De Oliveira and Burrini, 2009). ))) Aging-related changes including the loss of enteric neurons and increased susceptibility to the adverse effects of medications. ))) Long-term use of stimulant laxatives, which can result in decreased bowel contractions and increased constipation (Petticrew et al., 2001). ))) Dysfunction in the pelvic floor muscles secondary to childbirth or hysterectomy, resulting in an immobile perineum and decreased descent of the pelvic floor during defecation (Rao, 1998) The longitudinal coat of muscle of the distal colon, which becomes complete in the sigmoid colon and rectum, is continuous with perineal muscle and fascia. ))) Medical conditions such as hypothyroidism, multiple sclerosis, Parkinson’s disease, Crohn’s disease, diabetes, celiac disease, irritable bowel syndrome, stroke, diverticulosis, cerebral palsy, and spinal cord injury, which can cause either sluggish intestinal contractions or chronic colonic spasm, both of which can slow down the movement of stool (Talley et al., 2003). ))) Use of constipating medications, including opiates, diuretics, antidepressants, antacids, antihistamines, iron preparations and anticonvulsants. Opiates, for example, decrease peristaltic contractions as well as the urge to defecate. Use of aspirin, acetominaphen and non-steroidal anti-inflammatory medications is also associated with chronic constipation (Chang et al., 2007). ))) Mechanical obstruction: The small or large intestines may compressed by tumors, hernias, prolapsed internal organs, chronic colonic spasm, the weight of a fetus during pregnancy or an accumulation of hard, dry feces. Intestinal adhesions which can narrow the lumen of the bowel may result from previous abdominal infections, blunt abdominal trauma, endometriosis, radiation treatment of the pelvis, and abdominal surgery, especially that of the large intestine, appendix or uterus (Barral, 2005; Dondelinger, 2004; Klingele, 2005; McKay and Hirano, 1998; Opoien et al., 2007) (see Figures 4 and 5). )) Emotional stress. The gastrointestinal tract contains both sympathetic and parasympathetic nerve fibers, and under emotional stress, sympathetic function predominates, contracting sphincters, constricting digestive system blood vessels and inhibiting both motility and secretion. Stimulation of the parasympathetic nerve supply of the colon increases its motor activity, while sympathetic stimulation decreases it. Conditions such as anxiety, depression and cognitive impairment may contribute to constipation ((Stam et al., 1997, Petticrew et al., 2001)) Victims of physical and/or sexual abuse during childhood are more likely to suffer from chronic constipation than control subjects who did not experience abuse. (Walling et al., 1994) Numerous case reports are available of successful treatment of constipation when the sole intervention was psychiatric (Clarke, 2007; Devroede et al., 1989; Drossman et al., 1990; Jarrell, 2003; Latimer, 1983; McMahon and Koltenburg, 2006; Mayer, 1993; Shorter, 1993).
Use of abdominal massage to treat chronic constipation
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Figure 3 “Stages of a Mass Movement of the Colon”, adapted from Hertz, A. F., Am J Physiolo 47: 57e65, 1913 A. The subject (an adult male with no gastrointestinal pathology) took 2 ounces of barium sulfate suspension along with breakfast. Five hours later, fecal material (the shadows at the end of the ileum, the caecum and the ascending colon) was visible. B. The subject then ate a lunch of meat, vegetables and pudding. The end of his ileum emptied rapidly during the meal, while his caecum and ascending colon filled. Towards the end of the meal, a large round mass at his hepatic flexure became cut off from the rest of his ascending colon. C. Immediately after the meal was finished, some of the mass moved slowly around his hepatic flexure. D. The diameter of the separated portion suddenly became much smaller and the large round shape changed into a long narrow one which extended from his hepatic flexure almost to his splenic flexure. E. After a few seconds, the long narrow shape developed haustral segmentation. F. Five minutes later, the long narrow shape suddenly become more elongated and passed around his splenic flexure. G. The long narrow shape immediately passed down his descending colon H. The long narrow shape immediately passed into the beginning of his sigmoid colon
stool. In one case, moderate hand pressure to the lower abdomen elicited measurable waves of rectal muscle contractions in a patient within 10 s (Sakakibara, R., personal communication, Dec 20, 2009, sakakibara@ sakura.med.toho-u.ak.jp).
Figure 4 “Small bowel obstruction secondary to adhesion from abdominal surgery” reprinted from Ros, P., “CT and MRI of the Abdomen and Pelvis: a Teaching File, second edition”, Baltimore: Lippincott, Williams and Wilkins, 2007.
Symptoms In addition to a reduced number of bowel movements, symptoms of constipation also include straining during defecation, slower colonic transit time, hard lumpy stools, abdominal distention and pain, sensations of incomplete defecation, decreased mood, decreased enjoyment of life, and sometimes limitations in recreation and work (Clarke et al., 2008; Dennison et al., 2005; Johanson et al., 2007). Chronic straining to pass stool can lead to physical changes, including hemorrhoids, hernias, anal fissures, laxity of colonic muscle fibers, thickening of the colonic wall as a result of the high pressure needed to push hard stool along, and activation of myofascial trigger points (Travell et al., 1999). During a bowel movement, a bolus of hard feces pressing against the left iliopsoas muscle can cause referred pain in that muscle’s pain referral area (Travell et al., 1999). Increased intra-colonic pressure secondary to constipation can lead to weakness in the colon walls, particularly in the sigmoid colon, predisposing patients to diverticulosis (ADA, 2008). Long-term use of laxatives may be a risk factor for the development of colonrectal cancer, possibly because toxicants have more time to be absorbed by the lining of the colon (Brocklehurst et al., 1998; Jacobs, 1998; Roberts et al., 2003; Watanabe et al., 2004). Other complications that can develop from chronic constipation include decreased rectal sensitivity,
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Figure 5 “Constipation due to pelvic organ prolapse: anterior rectocele (herniation of posterior vaginal wall) caused by vaginal childbirth”, reprinted with permission from Ros, P., “CT and MRI of the Abdomen and Pelvis: a Teaching File, second edition”, Baltimore: Lippincott, Williams and Wilkins, 2007.
fecal impaction, incontinence, and even bowel perforations (Kamm and Lennard-Jones, 1990).
Discussion The two randomized controlled trials performed since 1999 indicate that abdominal pressure or massage increases peristalsis, and thus could be helpful for increasing bowel function and decreasing chronic constipation (Lamas et al., 2009, and Le Blanc-Louvry et al., 2002). In addition, the 6 observational studies and 4 case reports that have appeared since Ernst’s call for further research add weight to the evidence for the effectiveness of abdominal massage. Despite the fact that there were many variations in the massage technique, amount of pressure applied, whether a patient or a healthcare professional performed it, how it was applied (even pressure from a machine stimulated peristalsis), the number of sessions and the duration of the studies, in each case massage was still effective in reducing constipation. In most, massage was performed by a healthcare professional, but in 2, massage was self-administered. Sometimes other interventions were combined with abdominal massage, such as aromatherapy, chiropractic manipulations or dietary changes. (In Lamas’s 2009 and Liu’s 2005 studies, however, neither fluid, fiber intake or exercise was altered). Participants’ health status also varied widely. Professional massage practitioners have often noted that manual pressure over the abdomen can stimulate bowel sounds, passage of flatus, and/or bowel movements. For over 25 years, the author has witnessed bowel movements occurring during infant massage classes when abdominal
M. Sinclair massage is performed by parents, and during massage sessions, constipated older children and adults having to visit the bathroom immediately after abdominal massage. The mechanisms behind abdominal massage’s constipation-reducing effect are not fully understood, but are most likely are a combination of stimulation and relaxation. Direct pressure over the abdominal wall alternately compresses and then releases sections of the digestive tract, briefly distorting lumen size and activating stretch receptors that can reinforce the gastrocolic reflex and trigger intestinal and rectal contraction (Brookes et al., 2004). Liu found that pressure on the lower abdomen elicited measurable waves of rectal muscle contraction in a spinal cord injured patient with viral myelopathy, a condition similar in outcome to a spinal cord injury. The patient typically had no ability to strain when attempting to defecate, with only small, infrequent, rectal muscle contraction. When her abdomen became distended with feces, the patient applied moderate pressure to her lower abdomen, using a rolling motion of her hand which elicited the waves of rectal muscle contraction and intermittent defecation through her anal sphincter. (Sakakibara, R., personal communication, Dec 20, 2009) Case reports by Harrington, Shirreffs and Preece found abdominal massage was helpful for constipation due to muscle weakness or slowed colonic motility induced by medications (Harrington and Haskvitz, 2006; Preece, 2002; Shirreffs, 2001). Liu concluded that the massage might trigger defecation not only through activation of intestinal stretch receptors, but also by stimulating somato-autonomic reflexes (Liu et al., 2005) Colonic transit time may be decreased by this mechanism (Ayas et al., 2006). Abdominal massage may affect also constipation by a very different mechanism, that of stimulating the parasympathetic nervous system, thus decreasing abdominal muscle tension, increasing motility of digestive tract muscles, increasing digestive secretions, and relaxing sphincters in the digestive tract. In Lamas’s study, the massage employed was a light rhythmic touch, performed in an environment designed to enhance relaxation (Lamas et al., 2009). Diego et al found that abdominal massage in premature infants could measurably increase vagal activity and gastric motility (Diego, 2005). An earlier case report of abdominal massage for a chronically constipated patient with abdominal spasticity due to cerebral palsy reported that 30 min after abdominal massage, the patient typically had a bowel movement without an enema: the author concluded that the release of abdominal muscle tension through massage increased peristalsis. (Emly, 1998). Given the current evidence, it is unlikely that stool is manually propelled along the digestive tract towards the rectum during abdominal massage, as some early practitioners believed.
Conclusion Abdominal massage has measurable effects upon constipation, either low muscle tone through stimulation, or spasmodic muscle states through relaxation. However, neither of these effects would result in stool being
Use of abdominal massage to treat chronic constipation manually propelled along the digestive tract towards the rectum. Abdominal massage can stimulate peristalsis, decrease colonic transit time, increase the frequency of bowel movements in constipated patients, and decrease the feelings of discomfort and pain that accompany it. Individual case reports show that massage has been effective for patients with chronic constipation due to a variety of diagnosed physiologic abnormalities and in patients with long-term functional constipation. There is also sound scientific evidence that massage can stimulate peristalsis in patients with post-surgical ilieus. Its effectiveness, lack of side-effects, and low-cost (especially if self-administered), make abdominal massage an attractive option in bowel management programs for persons with chronic constipation. One set of guidelines for holistic management of chronic constipation in primary care has been developed by a multi-professional group of healthcare practitioners in the United Kingdom. These guidelines combine abdominal massage with education of patients regarding toileting habits, exercise and diet, monitoring use of possibly constipating medications and prescribing laxatives if other methods have not been successful (Emly and Rochester, 2006). In cases where patients must receive constipating medications, such as the 87% of late-stage cancer patients who become constipated as a direct result of their opioid medication, the condition may add greatly to suffering from the patient’s actual disease (Petticrew et al., 2001; Riechelmann et al., 2007). Here, abdominal massage may significantly improve quality of life: it decreased constipation and associated abdominal discomfort in hospice patients (Preece, 2002). Drawbacks of abdominal massage include the need to perform massage repeatedly to see results, and to continue the massage for extended periods of time. There are a number of important questions on this topic that future research could address: for example, might the
443 effectiveness of abdominal massage depend upon the cause of the constipation? For example, is abdominal massage more or less effective when the constipation stems from an underactive thyroid or a diet lacking in fiber, than if it is caused by a spinal cord injury? And what if the functional constipation stems from pelvic floor dysfunction rather than slow-transit constipation or constipation-predominant irritable bowel syndrome? Further research is required to identify sub-groups of patients that might benefit from abdominal massage. Fruitful research might also be performed to identify the types of patients who would be the best candidates to learn self-massage. Abdominal massage techniques are not complex, and in two of the case studies, self-massage effectively relieved constipation. Many laypeople could be taught to perform this technique on a regular basis, much as they brush their teeth regularly. How long abdominal massage should be administered is also an important question investigation. One study which was conducted with elderly patients found constipation was decreased after only ten days of abdominal massage, and that the effect lasted for 7e10 days after massage was stopped, while Lama’s massage found no effect until 8 weeks of treatment (Kim et al., 2005; Lamas et al., 2009). A study investigating different pressure techniques could also be enlightening. Varying amounts have been used, from the light-pressure technique of Lamas to the moderate-pressure technique used by Preece (Kim et al., 2005; Jeon and Jung, 2005; Emly, 2001; Preece, 2002). A further question of interest is which techniques are the most effective in treating constipation. Some investigators found that Swedish massage was effective, however, mechanical massage has been effective as well. These techniques are far more alike than they are different.
Text box 2. A Typical Swedish Massage of the Abdomen for Constipation Contraindications include abdominal obstruction, abdominal mass, intestinal bleeding, abdominal radiation therapy, strangulated hernia and less than 6 weeks post-abdominal surgery. 1. Effleurage of the entire abdomen-10 times. 2. Effleurage of the rectus abdominis, external and internal obliques and transverse abdominis muscles-10 times each. 3. Kneading of the abdomen-3 times. 4. Clockwise effleurage over the presumed path of the colon-10 times. 5. Vibration of the small and large intestines-one minute, or more. 6. Repeat step 4. 7. Kneading over the presumed path of the colon, with the fist, heel of the hand or thumbs-one minute or more. 8. Petrissage over the presumed path of the colon-one time. 9. Vibration over the presumed path of the colon. 10. Repeat Step 4. Techniques used in different studies varied to some extent: for example, Lamas et al. (2009) used primarily lightpressure effleurage of the abdomen for a total of 7 min, while Emly (2001, 2006) used moderate-pressure effleurage, kneading and vibration, for a total of 15e20 min, while Preece (2002) used propulsive massage, for a total of 10 min.
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445 Shan, N., et al., June 2008. Ambulatory care for constipation in the United States, 1993e2004. American Journal of Gastroenterology 103 (7), 1746e1753. Shirreffs, C.M., May 2001. Aromatherapy massage for joint pain and constipation in a patient with Guillian Barre. Complementary Therapies in Nursing and Midwifery 2 87e83. Shorter, E., 1993. From Paralysis to Fatigue: A History of Psychosomatic Illness in the Modern Era. Free Press, New York. Sinclair, M., 2004. Pediatric Massage Therapy. Lippincott, Williams and Wilkins, Baltimore. Southwell, B.R., et al., Jul 2009. Colonic transit studies: normal values for adults and children with comparison of radiological and scintigraphic methods. Pediatric Surgery International 25 (7), 559e572. Stam, R., et al., June 1997. Trauma and the gut: interaction between stressful life experiences and intestinal function. Gut 40 (6), 704e709. Starr, L., 1903. Hygiene of the Nursery: Including the General Regimen and Feeding of Infants and Children; Massage and the Domestic Management of the Ordinary Emergencies of Early Life. P Bakiston’s Son and Co, Philadelphia. Talley, N., et al., 2003. Risk factors for chronic constipation based on a general Practice Sample. American Journal of Gastroenterology 98, 1107e1111. Talley, N., 2004. Definitions, Epidemiology, and Impact of chronic constipation. Reviews in Gastroenterological Disorders 4 (Suppl. 2), S3eS10. Travell, J., Simons, D., Travell, J., 1999. Travell and Simon’s Myofascial Pain and Dysfunction: The Triggerpoint Manual. In: Upper Body, second ed., vol. 1. Lippincott, Williams and Wilkins, Baltimore, Maryland, pp. 953e959. Van de Berg, M.M., et al., Oct 2006. Epidemiology of childhood constipation. American Journal of Gastroenterology 101 (10), 2401e2409. van der Sijp, J.R., et al., March 1993. Radioisotope determination of regional colonic transit in severe constipation: comparison with radio opaque markers. Gut 34 (3), 402e408. Wald, A., et al., 2008. A Multinational survey of Prevalence and Patterns of laxative use among adults with self-Defined constipation. Alimentary Pharmacology and Therapeutics 28 (7), 917e930. Walling, Mary, et al., 1994. Abuse history and chronic pain in women: II. A multivariate analysis of abuse and psychological morbidity. Obstetrics and Gynecology 84 (2). Watanabe, T., et al., 2004. Constipation, laxative use, and risk of colorectal cancer: the Miyagi Cohort Study. European Journal of Cancer 40 (14), 2109e2115. Whorton, J., 2000. Inner Hygiene: Constipation and the Pursuit of Health in Modern Society. Oxford University Press, New York, 149 pp.
Journal of Bodywork & Movement Therapies (2011) 15, 446e452
available at www.sciencedirect.com
journal homepage: www.elsevier.com/jbmt
OUTCOME MEASUREMENT STUDY
Does the Feldenkrais Method make a difference? An investigation into the use of outcome measurement tools for evaluating changes in clients* Karol Anne Connors, M PT, CFP a,*, Carolyn Pile, B App Sc (OT), CFP b, Margo Elaine Nichols, MA, B SW, CFP a b
Calvary Health Care Bethlehem, Melbourne, Australia Latrobe Valley, Victoria, Australia
Received 11 August 2010; received in revised form 1 September 2010; accepted 5 September 2010
KEYWORDS Outcome measures; Functional tasks; PSFS; Quality of life; Pain outcome profile (POP)
Summary Evidence-based practice confirms the need for outcome measures. Feldenkrais Method practitioners struggle to use such tools because of the broad range of applications of the Feldenkrais Method and the difficulty identifying suitable measurement tools. A pre/ post-test design was used to investigate the use of three outcome measurement tools [Patient-specific Functional Scale (PSFS), Pain Outcome Profile (POP) and Short Form12v2 Health questionnaire (SF12v2)] for clients experiencing problems performing everyday functional tasks who attended Feldenkrais sessions. Eleven Feldenkrais practitioners submitted data on 48 clients. Changes were detected in the clients’ ability to perform everyday tasks (PSFS improved 3.8 points, p < 0.001), levels of pain decreased (POP improved in current pain p Z 0.001, physical index p < 0.001 and affective index p Z 0.001) and quality of life improved significantly in six of the eight SF12v2 domains. These three tools have been found to be suitable for detecting changes in client function before and after a series of Feldenkrais sessions. Crown Copyright ª 2010 Published by Elsevier Ltd. All rights reserved.
Introduction Background * Institution: This project was conducted under the auspice of the Australian Feldenkrais Guild. * Corresponding author. 29 Rusden St, Brighton 3186 Vic, Australia. Tel.: þ61 39595 3441; fax: þ61 39595 3249. E-mail address:
[email protected] (K.A. Connors).
Outcome measures have become increasingly important over the past few decades in many fields of endeavour. Particularly in the area of health, people have become interested in evaluating and comparing intervention
1360-8592/$ - see front matter Crown Copyright ª 2010 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.09.001
Does the Feldenkrais Method make a difference? outcomes, rather than relying on practitioners’ assertions of efficacy. Outcome measures can be useful for identifying changes due to an intervention both in research and in individual clientepractitioner interactions. Outcome measures attempt to determine the effects of an intervention by measuring certain elements associated with that intervention. It is important that researchers identify elements that are central to the intervention being studied. Outcome measurement tools must also be reliable and valid. In other words, the tool must be able to be relied upon to deliver consistent results and to measure what it sets out to measure. For this study, measurement tools needed to be quick and easy to complete as they were to be used in authentic client sessions. The Feldenkrais Method uses an exploratory learning approach to help people move with more ease, comfort and efficiency (Wildman, 2000 p. 4). There is plenty of anecdotal evidence to suggest that the Feldenkrais Method is beneficial for clients, but there have been relatively few studies which have vigorously investigated its effectiveness. Several studies have identified significant improvements in balance-related outcomes (Gutman et al., 1977; Bennett et al., 2001; Hall, 2001; Batson and Deutsch, 2005; Stephens et al., 2001; Connors et al., 2009; Vrantsidis et al., 2009; Ullmann et al., 2010). Other studies have found improvements in chronic pain (Bearman and Shafarman, 1999), back pain (Smith et al., 2001), hamstring length (Hopper et al., 1999; Stephens et al., 2006) and other musculoskeletal disorders (Lundbland et al., 1999; Malmgren-Olsson and Branholm, 2002) in clients receiving Feldenkrais interventions. There have been relatively few studies investigating the effects of the Feldenkrais Method on musculoskeletal problems, despite these problems being a common reason why clients seek the assistance of a Feldenkrais practitioner.
Outcome measurement tools The cohort used for this study was adults with problems affecting their ability to physically function in their everyday lives. The outcome measurement tools were chosen to measure this capacity. Three tools were selected for this pilot program. They were the Pain Outcomes Profile (POP), the Patient-Specific Functional Scale (PSFS) and the SF12v2 (a health-related quality of life questionnaire). The Patient-Specific Functional Scale (Stratford et al., 1995) evaluates how well a person is performing certain activities e activities which the clients self select as being important for themselves in their everyday lives. This tool was developed by Canadian physiotherapists and has been successfully used to evaluate responses to treatment for people with neck pain, knee pain, wrist and hand injuries and low back pain (Sterling and Brentnal, 2007; McMillan and Binhammer, 2009). The PSFS has also been found to have construct and predictive validity as an indicator of functional limitation in workers compensation claimants; the PSFS was able to predict return to work and recovery, with decreasing scores relating to delayed recovery (Gross and Asante, 2009). As it could be expected that most of the clients in this study would be seeking assistance with musculoskeletal problems and experiencing pain, it was decided that the
447 POP would be an appropriate outcome measure. This tool was developed by the American Academy of Pain Management and has undergone reliability and validity testing which has demonstrated that it is a reliable and valid tool (Clark et al., 2003). The Feldenkrais Method claims to engage the whole person, including how a person thinks, feels, acts and senses, therefore it was decided to also use a putatively more holistic tool that measures health-related quality of life. The SF12v2 questionnaire (entitled “Your Health and Wellbeing”) is a widely used and well recognized quality of life survey which investigates both the physical and emotional domains of health and wellbeing (Cheak-Zamora et al., 2009) that have been developed by the QualityMetrics organization based in the United States. The questionnaire has undergone rigorous testing during its development to ensure that it is a valid and reliable tool for measuring self-rated quality of life (Ware et al., 2008).
Study aims The primary aim of this study was to establish if three selected measurement tools would be suitable for measuring client outcomes following Feldenkrais intervention. A secondary aim was to facilitate future research into the Feldenkrais Method.
Methodology Practitioners’ role Australian Feldenkrais Guild (AFG) practitioners were invited to participate in the study. Each practitioner who registered to participate had a study mentor assigned to assist them. The mentors were three Feldenkrais practitioners with experience in research who designed the study, selected the outcome measures and arranged permission to use them, distributed and collected the surveys and collated the results. Each participating practitioner was asked to administer the three questionnaires before starting the Feldenkrais sessions, with 5e10 new clients and to repeat the questionnaires at the end of these client’s series of sessions. A time frame of 6 months was set for data collection. The research methodology was approved by the Australian Feldenkrais Guild and written consent was gained from each client prior to commencing in the study. Clients were excluded from the study for three reasons: if they were under 18 years old, had insufficient English language skills to complete the questionnaires or did not present with any functional problems, for example, a client who wished to improve her professional singing was excluded. Background data was collected on age; gender; purpose of visit and length of symptoms prior to presentation.
Procedures for use of the outcome measurement tools The clients identified three activities targeted for improvement. The clients rated the performance of each activity (scored between 0 and 10 on the PSFS and then
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averaged) before and after the Feldenkrais series of lessons. The practitioner discussed these activities with their client at the first session to assist in completing the form and as part of the practitioners’ initial information gathering about the functional goals of their client. Although the practitioner assisted their client in describing the activities on the PSFS in a precise manner to make it easier to re-score the activities, the practitioner did not assist the client with choosing a rating score for each activity. For example, a client-identified activity which he/ she wanted to improve may have been “sitting at work”. This activity may have been refined by the client and practitioner jointly to read “sit at work at the computer for 1 h without pain”. The POP produces information about several aspects of the clients’ self-rated pain. One question concerns the client’s pain at that moment in time (Current Pain), rated from ‘0’ (no pain) to ‘10’ (worst possible pain). In accordance with the POP scoring guidelines, scores on the POP items relating to mobility, activities of daily living and vitality were aggregated together to comprise a ‘Physical Index’ and items relating to affect and fear were aggregated to form an ‘Affective Index’. These scores indicate how much the pain is interfering with the person’s ability to function, so a lower score means that the pain is having less of an impact. The results for the SF12v2 are divided into eight domains with a maximum possible score of 100 for each domain. Both the POP and SF12v2 are standardized measures that have scoring instructions which transform the raw data into aggregated scores representing various emotional, physical and social domains (Ware et al., 2008). These instructions were followed to produce the scores which are presented in the results section. Both the POP and the SF12v2 involved the client circling numbers or words on the survey to
Table 1
Domains of the SF12v2 health survey.
Domain
Description
Physical functioning
Ability to perform activities ranging from dressing oneself to climbing a flight of stairs. How the health problems have impacted on the person’s ability to accomplish and perform in their life. Pain severity and impact. Health in general and in comparison to others. Feelings of energy or feeling tired and worn out. How the health problems have impacted on the person’s social roles and activities. How the person’s feelings have impacted on what they do and how they do it. The person’s state of mind related to feelings such as anxiety, happiness and sadness.
Role physical
Bodily pain General health Vitality Social functioning
Role emotional
Mental health
complete the questionnaires. The clients completed the POP and SF12v2 on their own without assistance from the Feldenkrais practitioner. Table 1 describes the domains for the SF12v2 produced by aggregate scoring.
Sample size The SF12v2 guidelines of “sample sizes needed to detect differences over time within one group” (Ware et al., 2008)(p 64), states that twenty-three subjects are needed to give 95% confidence that 5 points of difference in scores between pre- and post-testing is not due to measurement error. The study aimed for a sample size of 50 subjects to allow for potential missing data due to the communitybased clinical setting used in this study. If clients did not complete all the questionnaires, practitioners were asked to include comments on why this had happened.
Data analysis To determine if there had been significant changes in the scores on the surveys before and after the Feldenkrais sessions, pre- and post-scores on each survey were compared, using two tailed paired samples T-tests. The results were analysed using SPSS statistical analysis software1. A significance level of p Z 0.05 was set.
Results Practitioner involvement Of the 29 Feldenkrais practitioners who originally registered interest in participating in the study, eleven practitioners submitted client data. Data was submitted on 48 clients. The practitioners who submitted data were spread across Australia (Victoria 3, Western Australia 3, New South Wales 2, Queensland 2 and South Australia 1). These practitioners had an average of 14.1 years since graduation from Feldenkrais training programs.
Client attrition and incomplete data There was complete data returned on 33 clients. There was missing data on re-testing for the other 15. Practitioners failed to report a reason why there was incomplete data for four of these clients. For three other clients, the practitioners forgot to do the post measures. Of the other eight clients with no ‘post’ data, three had moved away or went on holidays and the remaining clients were lost to the study due to a variety of reasons including a fractured ankle, surgery and not attending for re-testing. One data set was excluded during data analysis as the client was under 18.
Participant and Feldenkrais sessions characteristics Table 2 displays the characteristics of the clients involved in the study. Median scores are presented for the data on 1
Grad Pack 15, SPSS inc, Chicago, Illinois.
Does the Feldenkrais Method make a difference? Table 2
449
Participant characteristics.
Age (years)
Gender
Time period of symptoms prior to presentation (months)
Number of Feldenkrais sessions
Time period between pre- and post-testing (weeks)
Mean
Range
Female
Male
Median
Range
Mean
Range
Mean
Range
50.3
25 to 79
38
9
12
2 to 240
6.5
2 to 20
11.6
2.5 to 31
length of symptoms because the distribution of this data was skewed by one client having had symptoms for 20 years. The clients could be considered to have chronic symptoms, rather than acute, as the symptoms had been present for at least 2 months, and on average for 12 months. Clients had sessions on average once per fortnight during the treatment period, which averaged 11.6 weeks.
Patient-specific Functional Scale The mean scores for the clients before and after the series of sessions are displayed in Table 3. There was a statistically significant improvement between the pre- and postscores (p < 0.001).
Pain Outcome Profile Significant improvements between pre- and post-testing were found on all of the items on this questionnaire. A lower score represents less pain and the scores were found to nearly halve on the Current Pain item between pre- and post-testing (from 3.5 to 1.8). There were significant improvements in Current Pain (p Z 0.001), Physical Index (p < 0.00) and Affective Index (p Z 0.001). The results are presented in Table 3. Two of the clients failed to answer some questions in this questionnaire, which meant that the scores could not be transformed into Physical Index for two clients and the Affective Index for one of these clients. Another question on the POP asked the client “How long have you had the pain for which you are now seeking treatment?” and the responses to this question were included in the participant characteristics data in Table 2. A post hoc analysis was performed on the POP ‘Current Pain’ item, to determine the effect on the results of the 17 clients who only scored less than three out of ten at the initial testing. It was found that this group of clients minimally changed their mean score from 0.94 to 0.76 points (p Z 0.4),
Table 3
whereas the 18 clients who scored three or higher for current pain improved from a mean of 5.86 down to 2.72; this is a mean difference of 3.14 points (p Z 0.001).
SF12v2 health survey The mean scores for the participants before and after the Feldenkrais sessions are displayed in Fig. 1. All of the domains, except General Health and Vitality, were found to have changed significantly [Physical Functioning: 12.3 (95% CI 23.8e0.8) p Z 0.028; Role Physical: 21.3 (95% CI 34.7e7.8) p Z 0.004; Bodily Pain: 24.5 (95% CI 32.7e16.2) p < 0.001; General Health: 1.8 (95% CI 8.4e4.6) p Z 0.56; Vitality: 10.9 (95% CI 27.4e5.6) p Z 0.24; Social Functioning: 14.1 (95% CI 25.5e2.6) p Z 0.016; Role Emotional: 15.1 (95% CI 23.8e6.4) p Z 0.002; Mental Health: 12.9 (95% CI 19.0e6.8) p < 0.001]. Fig. 1 also shows the mean scores for these domains in the United States (based on 1998 General US population means using a sample of 7069 people drawn from across the country) (Ware et al., 2008). These scores have been included to provide a comparison with the data from the current study.
Discussion This study evaluated three outcome measurement tools to test their usefulness in detecting changes in subjects in a real life setting. All three tools showed significant differences between before and after the Feldenkrais sessions. Indeed all the changes indicated improvements in the clients’ physical and emotional wellbeing. The clients and practitioners found the tools quick and easy to use with minimal explanation. Practitioners reported that the PSFS was the most useful of the questionnaires in practice. The PSFS helped the client to develop functional goals to be achieved in relation to attending the Feldenkrais sessions. The ratings of performance on these activities were useful
Results of Patient-specific Functional Scale (PSFS) and Pain Outcome Profile (POP). PSFS (n Z 34)
Mean score (SD)
POP current pain (n Z 35)
POP physical Index (n Z 34)
POP affective index (n Z 33)
Pre
Post
Pre
Post
Pre
Post
Pre
Post
3.6 (1.9)
7.4 (2.0)
3.5 (3.0)
1.8 (2.0)
28.8 (17.5)
20.6 (16.7)
39.7 (22.9)
26.9 (16.2)
450
K.A. Connors et al. **
Mental Health
*
Role Emotional
Social Functioning
*
Vitality
US Mean Pre Feldenkrais Post Feldenkrais
General Health
Bodily Pain
**
Role Physical
*
Physical Functioning
* 0
10
20
30
40
50
60
70
80
90
100
* denotes p <0.05 difference between pre and post scores, ** denotes p < 0.001 difference between pre and post scores.
Figure 1
SF12v2 scores pre and post-Feldenkrais sessions.
for both the practitioner and client to track the clients’ progress. However, clinicians and researchers must be aware that the PSFS can cause non-specific effects, as it identifies in advance particular changes which the client may then anticipate from the intervention. The 3.8-point average improvement in the PatientSpecific Functional Scale score was well above the 2 points identified as being the ‘Minimal Detectable Difference’ (90% Confidence Interval) needed to be sure that the change was not just due to measurement error (Sterling and Brentnal, 2007). The ‘Minimal Clinically Important Difference’ using the Patient-specific Functional Scale has also been reported to be a change in score of more than 2 points (Berghuis-Kelley and Scherer, 2007). The clients attending the Feldenkrais sessions improved their scores by an average of 3.8 points, suggesting that these clients were achieving clinically significant changes in their ability to perform functional tasks. Furthermore, Sterling and Brentnal (2007) identify how the PSFS helps the client to focus on positive aspects of functional recovery rather than dwelling on levels of pain. This approach is very congruent with the Feldenkrais Method approach, which seeks to return clients to their full potential rather than focusing on their impairments. Feedback from the pilot study suggested that both clinicians and clients found this tool to be the most acceptable of the three for use in a clinical setting. The PSFS can therefore be recommended for use both at the individual practitioner level for tracking client progress and setting functional goals, and also for future research studies into the Feldenkrais Method. The Pain Outcome Profile provided useful information about a client’s current pain as well as their physical and affective profile. This tool also provides the option of
a simple and effective graph for feedback to clients and practitioners. Clark et al. (2003) investigated the reliability and validity of this tool with United States veterans with current pain. They described Clinically Significant Differences for the Current Pain item to be 0.34, 0.85 and 1.35 for small, medium and large differences respectively. The clients in the current study had an improvement of 1.7 points, which can therefore be considered a large Clinically Significant Difference. When only the clients who initially scored three or over on Current Pain at baseline are included, the improvement of 3.14 points is well above the 1.35 points needed to be considered a large difference. A test-retest reliability study (Clark et al., 2003) on the POP found there was no change in score over time for people with chronic pain on this questionnaire when there was no intervention. The change in scores found in the current study was therefore unlikely to be solely due to retesting. The clients in this study had their symptoms for a significant length of time (a median time of 12 months) so to achieve almost uniform improvement in pain scores certainly warrants further investigation into the Feldenkrais Method. It is important to note too that the improvements were found after an average number of only 6.5 sessions. The SF12v2 was quite quick and easy for the clients to complete but the scoring is very complex and it is not necessarily suitable for use as a clinical tool. For research purposes however, it is a valuable tool which has been thoroughly investigated and is frequently used in clinical trials. The client group in the current study was below the United States norms on every initial measure, particularly on the physical items and for Bodily Pain. This suggests that they are indeed attending the Feldenkrais sessions because
Does the Feldenkrais Method make a difference? they are experiencing difficulties in their everyday lives. The results demonstrate an improvement in each item between pre- and post-testing, and the Emotional Role and Mental Health actually improve to higher than the United States norm on re-testing. This improvement in emotional items as well as physical ones is important, as it shows the close relationship between physical and mental health, and captures some of the emotional changes that the Feldenkrais Method claims to effect (Feldenkrais, 1990 p. 10e11,19). The smaller changes in General Health and Vitality compared to the other domains is interesting. It could be suggested that less change in these areas adds validity to the results, as one would not necessarily expect that a clients’ general health be affected by the Feldenkrais Method, as this is generally determined by illnesses which the Feldenkrais Method does not address. Another explanation might be that the clients in this study were closest to the United States norm score for General Health and Vitality at pre-testing, so there was less room for improvement in these domains. The average scores on the Vitality item did in fact change by 4.8 points e almost the 5 points recommended by Qualitymetrics as the amount of change needed to be sure the changes are not caused by measurement error (Ware et al., 2008). Whatever the reasons for the variations between the domains in the change scores, the fact that clients reported more changes in some domains than others suggests that the clients did not just uniformly score themselves higher on every item at re-testing but gave considered responses. The primary aim of this study was to facilitate future research into the Feldenkrais Method, partly by identifying suitable outcome measurement tools to use and partly by using an approach which could be followed by others. The involvement of several practitioners was a key element in this study. It enabled the recruitment of sufficient numbers of clients to make the study robust, without placing too much burden on any individual practitioner and their practice. Using data collected from several practitioners also eliminated problems of bias which may have arisen if all the data came from just one practitioner. Readers may have been concerned about both the skill of a single practitioner and if this data was truly representative of the Feldenkrais Method, but by including data from eleven practitioners in five different states we can confidently generalize these results to the Feldenkrais Method as a whole. Future research could build on this study in several ways. These measurement tools can now confidently be used by Feldenkrais researchers to evaluate changes to clients in other countries (how does data from the US or UK or Europe compare to these results?) or with specific client groups (eg. do clients with arthritis respond in the same way as clients with chronic back pain?). More importantly, research could be conducted using a Control group, who did not receive Feldenkrais intervention, and compare the results with those who did. That type of study (Randomised Controlled Trial) would provide the most solid evidence about the effects of the Feldenkrais Method. The researchers in this study appreciated the support from the Australian Feldenkrais Guild, who facilitated communication with practitioners and paid for the administrative costs of the project such as postage, printing and
451 licenses for the measurement tools. To encourage and support future research, more efforts need to be made to develop funding bodies which can support research in nontraditional areas and emerging areas of health.
Study limitations There was a relatively high level of dropouts and incomplete data in this study (15/48). This may have been due to the nature of the study. It was conducted in authentic clinical settings, by clinicians, spread across all of Australia with minimal research support. In hindsight, assisting practitioners to promptly follow-up clients who did not return for re-assessment would have been beneficial, as several participants did not have re-assessment data completed despite having attended several Feldenkrais sessions. Another limitation of this study is that it only included adult clients with difficulties performing everyday tasks. There are many applications for the Feldenkrais Method and the suitability of the outcome measurement tools examined in this study cannot be generalized for use in other client groups, such as performers or children with disabilities. Further research will be needed to assess the use of these or other measurement tools with different client groups. The authors also caution that there are many outcome measurement tools available for practitioners and researchers, and the three chosen for this study were considered to be the most useful for the purposes of this study. This does not mean that other measurement tools will not also be found to be useful, even with the current client group. Furthermore, the Feldenkrais Method endeavours to engage the client in a process of learning about themselves and how they act out their lives in the world. Some clients will continue to pursue this learning into exploring new ways of moving and acting that can result in profound changes in their lives. The types of quantitative outcome measurement tools used in this study only brush the surface of such changes in a person’s life, and need to be combined with more qualitative studies to fully understand the potential effects of the Feldenkrais Method.
Conclusions This study has demonstrated that the three outcome measurement tools selected in this study [the Patientspecific Functional Scale, the Pain Outcome Profile and the SF12v2] all showed statistically significant improvements in daily function, pain and health-related quality of life (except in the domains of General Health and Vitality in the SF12v2) after a series of Feldenkrais sessions. This suggests that these three outcome measurement tools are suitable for measuring changes resulting from Feldenkrais Method sessions for clients presenting with difficulties performing everyday functional tasks. The length of time clients had been experiencing their symptoms prior to commencing Feldenkrais sessions (a median time of 12 months) suggests that the changes were not simply due to spontaneous recovery.
452 The authors recommend that further research is conducted into the effectiveness of the Feldenkrais Method as an intervention to improve the ability of clients with pain and functional limitations to perform everyday activities.
References Batson, G., Deutsch, J., 2005. Effects of Feldenkrais Awareness through Movement on balance in adults with chronic neurological deficits following stroke: a preliminary study. Complementary Health Practice Review 10 (3), 203e210. Bearman, D., Shafarman, S., 1999. The Feldenkrais Method in the treatment of chronic pain: a study of efficacy and cost effectiveness. American Journal of Pain Management 9, 22e27. Bennett, J., Brown, B., 2001. Effects of a Feldenkrais based mobility program on function of a healthy elderly sample. In: Stephens, J. (Ed.), Research Studies. Feldenkrais Education Foundation of North America, USA. Berghuis-Kelley, D., Scherer, S., 2007. Outcome measures in cardiopulmonary physical therapy: use of the Patient Specific Functional Scale. Cardiopulmonary Physical Therapy Journal 18 (3), 21e23. Cheak-Zamora, N., Wyrwich, K., et al., 2009. Reliability and validity of the SF-12v2 in the medical expenditure panel survey. Quality of Life Research 18 (6), 727e735. Clark, M.E., Gironda, R., et al., 2003. Development and validation of the ain outcomes questionnaire. Journal of Rehabilitation Research and Development 40 (5), 381e396. Connors KA, Galea M, et al. 2009. Feldenkrais Method balance classes improve balance in older adults: a controlled trial. Evidence based complementary and alternative medicine advance (accessed 24.06.09). Feldenkrais, M., 1990. Awareness through Movement: Health Exercises for Personal Growth. Arkana, London. Gross, D., Asante, A., 2009. The Patient-specific Functional Scale: validity in workers compensation claimants. Archives of Physical Medicine and Rehabilitation 89 (7), 1294e1299. Gutman, G., Herbert, C., et al., 1977. Feldenkrais versus conventional exercises for the elderly. Journal of Gerontology 32 (5), 562e572. Hall, S., 2001. Study of the effects of various forms of exercise on balance in older women. In: Stephens, J. (Ed.), Research Studies. Feldenkrais Educational Foundation of North America, USA.
K.A. Connors et al. Hopper, C., Kolt, G., et al., 1999. The effects of Feldenkrais awareness through movement on hamstring length, flexibility and perceived exertion. Journal of Bodywork and Movement Therapies 3 (4), 238e247. Lundbland, I., Elert, J., et al., 1999. Randomised controlled trial of physiotherapy and Feldenkrais interventions in female workers with neck-shoulder complaints. Journal of Occupational Rehabilitation 9 (3), 179e194. Malmgren-Olsson, E.B., Branholm, I.B., 2002. A comparison between three physiotherapy approaches with regard to healthrelated factors in patients with non-specific musculoskeletal disorders. Disability and Rehabilitation 24 (6), 308e317. McMillan, C., Binhammer, P., 2009. Which outcome measure is best? Evaluating responsiveness of the disability of the arm, shoulder and hand questionnaire, the Michigan hand questionnaire and the Patient-specific Functional Scale following hand and wrist surgery. Hand 4, 311e318. Smith, A., Kolt, G., et al., 2001. The effect of the Feldenkrais Method on pain and anxiety in people experiencing chronic low back pain. New Zealand Journal of Physiotherapy 29 (1), 6e14. Stephens, J., Davidson, J., et al., 2006. Lengthening the hamstring muscles without stretching using “Awareness through movement”. Physical Therapy 86, 1641e1650. Stephens, J., DuShuttle, D., et al., 2001. Use of awareness through movement improves balance and balance confidence in people with multiple sclerosis: a randomized controlled study. Neurology Report 25 (2), 39e49. Sterling, M., Brentnal, D., 2007. Clinimetrics: Patient Specific Functional Scale. Australian Journal of Physiotherapy 53, 65. Stratford, P., Gill, C., et al., 1995. Assessing disability and change on individual patients: a report of a patient specific measure. Physiotherapy Canada 47, 258e263. Ullmann, G., Williams, H., et al., 2010. Effects of Feldenkrais exercises on balance, mobility, balance confidence, and gait performance in community-dwelling adults age 65 and older. The Journal of Alternative and Complementary Medicine 16 (1), 97e105. Vrantsidis, F., Hill, K.D., et al., 2009. Getting grounded gracefully: effectiveness and acceptability of Feldenkrais in improving balance. Journal of Aging and Physical Activity 17 (1). Ware, J., Kosinski, M., et al., 2008. User’s Manual for the SF-12v2 Health Survey. QualityMetric Incorporated, Lincoln, RI. Wildman, F., 2000. The Busy Person’s Guide to Easier Movement. The Intelligent Body Press, Berkeley.
Journal of Bodywork & Movement Therapies (2011) 15, 453e464
available at www.sciencedirect.com
journal homepage: www.elsevier.com/jbmt
ASSESSMENT TECHNOLOGY
Real-time stability measurement system for postural control Alpha Agape Gopalai, B. Eng (Mechatronics) Hons a, S.M.N. Arosha Senanayake, M. Eng, PhD a,*, Loo Chu Kiong, PhD, B.Eng (Mechanical) Hons b, Darwin Gouwanda, B. Eng (Mechatronics) Hons a a School of Engineering, Monash University Sunway campus, 2, Jalan Lagoon Selatan, 46150 Bandar Sunway, Selangor, Malaysia b Centre for Artificial Intelligence and Robotics, Multimedia University, Malacca, Malaysia
Received 25 June 2010; received in revised form 29 September 2010; accepted 19 October 2010
KEYWORDS Weighted center of pressure; Pressure concentrations; Instrumented platform; Postural response; Perturbed surface
Summary A method for assessing balance, which was sensitive to changes in the postural control system is presented. This paper describes the implementation of a force-sensing platform, with force sensing resistors as the sensing element. The platform is capable of measuring destabilized postural perturbations in dynamic and static postural conditions. Besides providing real-time qualitative assessment, the platform quantifies the postural control of the subjects. This is done by evaluating the weighted center of applied pressure distribution over time. The objective of this research was to establish the feasibility of using the forcesensing platform to test and gauge the postural control of individuals. Tests were conducted in Eye Open and Eye Close states on Flat Ground (static condition) and the balance trainer (dynamic condition). It was observed that the designed platform was able to gauge the sway experienced by the body when subject’s states and conditions changed. ª 2010 Elsevier Ltd. All rights reserved.
Introduction
* Corresponding author. Tel.: þ60 35514 6249; fax: þ60 35514 6001. E-mail addresses:
[email protected] (A.A. Gopalai),
[email protected] (S.M.N.A. Senanayake),
[email protected] (L.C. Kiong),
[email protected] (D. Gouwanda).
The essence of human motion is the maintaining of postural alignment while standing upright. Postural alignment affects postural control as it controls the amount of effort required by the body for support, against gravity (Kantor et al., 2001). The human body incorporates various mechanisms to achieve postural alignment, which is mainly influenced by the availability and validity of the visual and the somatosensory receptors. The visual and somatosensory mechanism
1360-8592/$ - see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.10.005
454 functions as inputs to the Central Nervous System (CNS) (Danis et al., 1998). The CNS provides referential context for postural adjustments, necessary to control the body balance (Raymakers et al., 2005). The maintenance of control in body balance together with postural alignment for stability and steadiness are crucial aspects to injury avoidance (Page, 2006). Over the years many tools and methodologies have been developed to study postural alignment and postural control of the human body in various conditions (Chaudhry et al., 2008). Stability and steadiness are often assessed as the amount of displacement made by the Center of Pressure (Danis et al., 1998; Nault et al., 2002; Allard et al., 2004; Dalleau et al., 2007). There are a number of equipments that clinicians use to gauge balance of individuals. The most common equipments were reviewed and discussed in Chaudhry et al., (2008). These included Force Plates, Balance Master and Equitest. Chaudhry et al., (2008) concluded the Balance Master and Equitest had the most relevance to daily life, due to its moveable support surface that emulates real life conditions. Other studies on balance had also reached a similar conclusion of moveable platforms (Allum et al., 2010; Carpenter et al., 1999; Bloem et al., 1998). The drawbacks of the equipments presented in Chaudhry et al., (2008) however, were the high cost involved in acquiring them and their large space requirements. Such equipment is not designed to be mobile, hence limiting its application to a clinical or laboratory setting. This work presents an alternative method to assess stability and steadiness. The alternative method involves the design of an instrumented force-sensing platform that measures the displacement in weighted center of the applied pressure between the human feet and the platform’s surface. These points are tracked over time to facilitate understanding of migration of the weighted center of applied pressure. The surface of the platform was instrumented with arrays of Force Sensing Resistors (FSR). Common parameters used for assessing postural control are the sway velocity, sway area and sway path. The authors in Siqueira et al., (2009) and Mann et al., (2010) measured sway velocities in order to assess postural control of subjects. A different approach was taken in Owen et al., (1998) which used the mean sway path to determine the deterioration of postural control in the presence of fatigue. The parameter measured in this work to assess postural control was the sway area, as was previously reported in Nardone et al., (1997) and ReedJones et al., (2008). Equipment that is commonly used to measure dynamic condition balance, such as the Balance Master and Equitest utilize dual force plates to individually measure the required parameters of each foot. Unlike the force sensing platform that uses FSR as its sensing element, the force plate utilizes load cell(s) to measure the vertical component in the geometric center of the platform. Load cells measure the average exerted force in a specific area covered. Due to its construction, single force plates are not able to provide parallel feet assessment, and would require an additional force plate for such measurement (one force plate per feet), as was reported in Jancova (2008). This work proposes a single force-sensing platform for parallel
A.A. Gopalai et al. foot assessment in determining the weighted center of applied pressure migration. The aim of this investigation was to study the feasibility of using FSRs as a basic sensing element to provide observers an alternative method, for qualitative measure of postural control and proprioceptive strength in real-time. The qualitative measure of proprioceptive strength was then used to describe the postural control (in static and dynamic states) for Eye Open (EO) and Eye Closed (EC) conditions (Siqueira et al., 2009). The platform presented in this work, addressed the cost constraint that was associated with current technologies (Chaudhry et al., 2008), while being portable in nature, allowing for on-site tests to be conducted.
Materials and methods The designed system, possesses two functionalities depending on its utilization, real-time or post-acquisition. Figure 1 briefly summarizes these two functionalities and the processes involved to obtain the final results. The processes are ordered according to the chronology of processes in the work.
Subjects The subjects for this study consisted of 18 healthy subjects (9 Males and 9 Females), volunteers from the community, aged between 20 and 30 years. All participants were healthy and had no known neurological or muscular disorder. The subject group had the following average readings, age Z 23.69 years (S.D. Z 2.39), mass Z 62.49 kg (S.D. Z 10.67), height Z 167.25 cm (S.D. Z 7.59) and Body Mass Index (BMI) Z 22.17 kg/m2 (S.D. Z 2.14). Before any readings were taken, the researcher went through in detail the entire purpose and procedure of the experiment. Subjects were informed on the potential hazards that may be involved during data collection. All subjects gave their informed consent to participate in this study. Safety hand rails were introduced to assist subjects mount the balance trainer, and served as support in event subjects lose balance during data acquisition, Figure 2. The tests were conducted in the laboratory for BioInspired Robotic Devices (BIRDs) of the School of Engineering, Monash University, Sunway campus with the ethic clearance from the Monash University Human Research Ethics Committee (MUHREC) (CF10/0762e2010000339).
Instrumented platform The instrumented platform is a force-sensing platform. The constructed platform was based on earlier concepts of a force-sensing device presented in Senanayake et al., (2007); Khoo et al., (2007), and Gouwanda and Senanayake, (2008). These studies utilized FSRs which are a polymer thick film device that exhibits a decrease in resistance with an increase in the force applied to the active surface, Figure 3(a). The change in resistance by these sensing elements were converted to voltage linearly. A platform of this nature must have adequate sampling rate, to ensure a complete profile capture during data acquisition.
Real-time postural stability measurement system
455 sampled by the host computer. Figure 3(b) illustrates the architecture of circuits implemented with the force sensing platform and how they relate to each other.
BOSU balance training platform The BOSU Balance Trainer is a unique balance, core stability and proprioception training device that is widely used by professionals and national athletes to help achieve body balance rapidly and safely. The platform provides an unstable balance surface when subjects stand on it. The force sensing platform was attached to the surface of the BOSU Balance Trainer, Figure 4. The force sensing platform had negligible movement over the BOSU surface because the platform was hinged to supports on the surface. The attachment of the force sensing platform allowed for the observation and evaluation of human postural control in dynamic conditions. The BOSU surface measured 635 mm in diameter (Figure 4(a)) and had a variable height, x mm (Figure 4(c)), depending on the amount of air introduced into its inflatable chamber. The perturbation experienced by the subjects once on the platform was not generated by electrical motors, controlled by computers or a program. The direction and angles of perturbation were solely dependent on the subjects’ body sway (i.e. perturbations were self inflicted). The balance trainer tilted in the direction of the net forces acting on the surface of the balance trainer. Figure 5 illustrates measurements taken by a gyroscope placed on board the balance trainer. The graphs depict the maximum and minimum amount of orientation that the subject may be subjected to whilst on the platform (z40 in both planes, Anterior-Posterior and Medial-Lateral). The introduction of the BOSU balance trainer allowed for investigation of immediate defensive postural reactions and the adaptation of postural control mechanisms when presented with an oscillatory surface. Figure 1 General overview of the process flow in the work presented.
Experimental procedures
The minimum sampling frequency for a platform of this nature is 50 Hz (Gouwanda and Senanayake, 2008), the designed platform has sampling rates of up to 200 Hz (all experiments were conducted at a sampling rate of 200 Hz). The designed force-sensing platform in this study measured 635 mm in diameter. This diameter was selected to ensure the largest possible instrumentation area allowing for natural foot positioning of subjects, ensuring readings acquired reflected naturally pathological conditions (Reed-Jones et al., 2008; Amiridis et al., 2003; Prieto et al., 1996). The platform was fitted with 122 units of FSR, arranged in a matrix form. Each FSR has a sensing area of 126.68 mm2 and was placed 40 mm apart (from the center of each sensing element). Raw signals from the sensors were then passed through a signal conditioning circuit in real-time before any further analysis. The FSRs were connected to non-inverting operational amplifier, for amplification of signal strength. Outputs from the operational amplifiers were in turn connected to a switching circuit before being
There have been many studies conducted in order to measure and to quantify human body sway under various conditions and environments (Blaszczyk et al., 2009; Pascolo et al., 2009; Lamoth et al., 2009). The common method of investigation was, the ability of the subjects to maintain body balance and posture in EO and EC states. The experimental procedures discussed in this paper adapts similar procedures established in Blaszczyk et al. (2009), Pascolo et al. (2009) and Lamoth et al. (2009). All acquisitions were captured in barefoot conditions, to ensure that the force profile readings acquired were not averaged due to the soles of the subjects’ footwear (Urry, 1999) and to provide sensorimotor maximum amount of appropriate afferent information (Page, 2006). Visual feedback was provided to end-users for observation of force concentration in real-time. The subject’s vertical projection of force (while on the force sensing platform) was recorded for both states (EO and EC) in both conditions (static and dynamic), and was stored on board a computer. The host computer sampled the instrumented platform via a Data Acquisition (DAQ) card (National Instrument’s PCIMIO-16E-1).
456
A.A. Gopalai et al.
Figure 4 (a)e(d) Technical drawing of the balance trainer (e) the force sensing platform mounted on the balance trainer for acquisition of readings to simulate perturbed conditions.
was called static condition because the base of support on which the subjects stood, was firm.
Figure 2 Subject mounted on the balance trainer fitted with the force-sensing platform and hand rails for additional safety support in dynamic condition.
Flat groundestatic condition Subjects were required to maintain body balance for 30 s in EO while standing on the force sensing platform placed on flat ground followed by a second set of readings for 30 s, in EC. This arrangement was alternated between acquisitions, for 3 pairs of EO and EC readings. This served as the basal data for subjects. Subjects were allowed to take breaks in between each pair of acquisition, if required. The method
Perturbed surfaceedynamic condition Subjects were required to mount the balance trainer fitted with the force-sensing platform (on the balance trainer’s surface) for 30 s in EO, followed by 30 s, in EC. The base of the balance trainer is convex, designed to challenge postural control of subjects, Figure 2. Breaks were introduced between each pair of readings (EO and EC) before resuming with the next pair of readings, in order to eliminate the effect of fatigue on postural sway (Nardone et al., 1997, p309). Data was logged for 3 pairs of readings. This section of the experiment was termed dynamic due to the progression of instability of the base of support. The base of support was dependent on the subjects’ body sway (perturbations are self inflicted). The balance trainer tilts in the direction of the net force exerted on its surface.
Data analysis In static and dynamic conditions, subjects’ force profile was acquired from the FSRs. Signals from FSRs were sampled via
Figure 3 (a) Force Sensing Resistors (FSR), exhibits a decreases in resistance with an increase in the force applied to its sensing area/surface. (b) Architecture of circuits for force sensing platform, beginning at the sensing element (FSR) to the sampling process by the host computer.
Real-time postural stability measurement system
Figure 5
457
Range of perturbation induced by the balance trainer (a) in the M/L plane and (b) in the A/P plane.
the DAQ Card and passed through a moving averaging filter. The moving average filter technique was used to smooth out high frequency fluctuations that may be present in the sampled data due to electrical noise. This filtering technique was specifically chosen for its simplicity which reduces execution time, which is a crucial feature in a realtime feedback application. The acquired force profiles were displayed visually in real-time for qualitative assessments. The readings were also stored on board the host computer for post-acquisition analysis. Stored data sets can be retrieved for further analysis to quantify postural control. The proprioceptive strength of an individual is demonstrated by the ability to maintain the body posture in its ‘neutral’ position. An individual with good proprioceptive strength demonstrates a well controlled displacement of the COP for both EO and EC trials in static and dynamic conditions (Jancova, 2008). Visual representation of data The real-time output of the force-sensing platform was formatted according to the rainbow color scale. A rainbow color scale represents low force intensities with colors closer to black (cold colors), while high force intensities with colors closer to white (hot colors). This form of real-time feedback to end-users eases the identification of regions with high force concentrations by the foot, Figure 6(a). For data representation in post-acquisition, the data set was first checked for redundancy. Redundancy in the data sets referred to regions of the platform that did not come in contact with the subjects foot. A simple thresholding algorithm was applied to the acquired data set to isolate the areas of the redundant data points using equations (1)e(4). Since the force-sensing platform consists of FSRs arranged in a matrix form, each sensing unit can be individually identified as elements of a matrix. Let m be the total number of rows and n be the total number of columns, while the sensor matrix is represented in the data set as FSR and T a pre-determined threshold value. Figure 6(b) depicts the final result of applying equations (1)e(4), the boundary of the foot can now be plotted for ease of visualization.
m X In Z FSRði; : Þ
ð1Þ
iZ1 n X Im Z FSRð :; iÞ
ð2Þ
iZ1
fIn : Im TgðRegion is in contactÞ
ð3Þ
fIn : Im < TgðRegion is not contactÞ
ð4Þ
Identifying pressure concentration regions During the real-time feedback monitoring process (to the end-user), pressure concentrations were easily detected as depicted in Figure 6(a) (Qualitative method). These pressure concentration regions do not provide substantial quantitative relationship between balance control and foot pressure details. Hence, post-processing of the acquired data in its time series is required, to provide end users with a quantitative measure of the subject’s balance and postural control. Regions with high concentration of pressure collected over time are of interest in this study
Figure 6 Foot boundaries (a) Real-time feedback snapshot, depicting regions of high force concentrations (b) Reproduced foot boundary from reduced data set indicating regions of weighted center of the applied pressure over time.
458
A.A. Gopalai et al. Figure 7, depicts a portion of the force sensing platform (consisting of four FSRs arranged in a two-by-two matrix). The FSRs are distributed symmetrically in a similar manner across the force sensing platform. Equations (5) and (6) were applied across the force sensing platform recursively. At the end of the calculations, the acquired force profile was represented by FY , which is the total force acting perpendicularly on the foot at coordinates (X,Z ) per data sweep. A data sweep refers to the sampling of all 122 FSRs in a single clock cycle.
Figure 7 Magnitude and location of the resultant force FY calculated from the combined signals of the FSRs.
because it shows exactly which part of the foot the subject was using to maintain the ‘neutral’ position while standing, Figure 6(b). In this work, the pressure concentrations were calculated as the weighted center of applied pressure, which is referred to in this work as weighted center of pressure (COP). The COP of each foot was calculated using (5) and (6) to obtain the COP along the X-axis (Medial-Lateral, ML) and the Z-axis (Anterior-Posterior, AP). The equations in (5) and (6) results in the physical location (1 unit corresponds to 40 mm on the platform) of the weighted center of applied pressure (X,Z ), per data sweep. To obtain the time series of the migration of the COP this calculation was performed on the entire data sweep.
x ðFSRXO þ FSRXZ Þ ðFSROO þ FSROZ Þ XZ 1 þ 2 FY
ð5Þ
z ðFSROZ þ FSRXZ Þ ðFSROO þ FSRXO Þ ZZ 1 þ 2 FY
ð6Þ
FY ZFSROO þ FSRXO þ FSROZ þ FSRXZ
ð7Þ
The measure of postural control The mean value of the subject’s COP was calculated for each plane, to determine the range of postural sway experienced by the subject. Readings acquired from the subjects were averaged across the three collected sets, the standard deviations were also obtained and tabulated. The sample set was accepted as a valid COP reading if and only if the calculated value was within 95% interval (1.97 standard
Figure 8 Screen shots of of real-time readings from the platform at certain point in time (a) EO state in static condition (b) EC state in static condition (c) EO state in dynamic condition and (d) EC state in dynamic condition.
Real-time postural stability measurement system
Figure 9
459
Shift in COP on flat ground (a) Left Foot in EO (b) Right Foot in EO (c) Left Foot in EC (d) Right Foot in EC.
deviations - normal distribution assumed). The maximum and minimum values along the X and Z axes for each foot were identified. The area which contained 95% of the COP distribution was obtained. The area of this distribution was a key indicator of the subject’s postural control and proprioceptive strength. Subjects who demonstrated a large distribution area, tend to have a poorer postural control, distribution area and postural control are inversely proportional to each other (Lamoth et al., 2009; Jancova, 2008; Dalleau et al., 2007).
Results and analysis Real-time data representation The rainbow color scale visualizes the real-time output of the force-sensing platform. This method of representation provided real-time visual qualitative assessment of subjects in static and dynamic conditions. Figure 8 shows an example of the real-time feedback observed by users. End-
users can easily identify pressure points on the subject’s feet (white regions). This was due to the proprioceptors at the foot keeping the body in its ‘neutral’ position (Winter et al., 2003).
Analysis of postural Response in static conditions Figure 9(a) and (b) illustrates the shift in the calculated COP in EO on flat ground. Figure 9(c) and (d) illustrates the shift in the calculated COP in EC on flat ground. Results of the tests for static condition in EO were tabulated in Table 1 while the results for EC were tabulated in Table 2. The AP and ML measures in the tables are in terms of units of the force-sensing platform. The area of distribution was calculated based on the range of AP and ML of the left and right foot.
Analysis of postural Response in dynamic conditions This section of the results looks at the balancing capabilities of the subjects in dynamic conditions. Figure 10(a) and (b) illustrates the shift in the calculated COP in EO on the
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Table 1 Range of calculated COP per foot for each subject and the average area of distribution, in static condition for EO conditions. Sub
Left EO ML
F1 F2 F3 F4 F5 F6 F7 F8 F9 M1 M2 M3 M4 M5 M6 M7 M8 M9
2.49 3.78 4.24 4.67 3.93 4.79 3.36 4.84 5.27 3.71 2.66 4.14 4.27 3.74 3.35 3.32 4.50 4.99
AP
0.005 0.013 0.008 0.022 0.016 0.042 0.040 0.009 0.013 0.005 0.008 0.021 0.041 0.042 0.029 0.065 0.048 0.099
Area(mm2)
Right EO
7.13 6.00 7.62 8.03 7.27 6.74 5.95 7.93 9.10 7.93 5.88 6.83 7.51 5.75 6.00 5.99 6.53 6.31
ML
0.016 0.030 0.018 0.030 0.052 0.067 0.086 0.148 0.053 0.014 0.025 0.039 0.042 0.044 0.051 0.029 0.081 0.111
balance trainer that were introduced to emulate dynamic conditions. Figure 10(c) and (d) illustrates the shift in the calculated COP in EC on a movable platform. Results of the tests for dynamic conditions in EO was tabulated in Table 3 while the results for EC was tabulated in Table 4. The AP and ML measures in the tables are in units of the force sensing platform.
8.38 9.46 9.30 9.78 9.30 9.88 9.28 9.76 8.63 9.40 8.75 9.64 9.66 9.30 9.67 8.84 9.48 9.40
AP
0.012 0.007 0.405 0.019 0.041 0.020 0.033 0.079 0.084 0.006 0.013 0.014 0.018 0.007 0.025 0.015 0.008 0.018
6.29 5.50 7.99 6.25 7.99 5.00 5.40 6.01 6.07 6.58 5.41 5.77 6.41 5.01 6.54 4.53 5.90 5.04
0.026 0.053 0.074 0.152 0.074 0.108 0.118 0.134 0.239 0.036 0.032 0.066 0.015 0.027 0.028 0.025 0.067 0.017
9.99 19.94 80.66 90.93 98.28 127.18 185.89 303.80 529.05 6.92 15.17 44.62 51.02 52.01 55.31 58.81 112.97 290.83
Discussion The shifts observed in pressure distribution from the graph for standing in static conditions (EO and EC) oscillates within a small concentrated region Figure 9. The EO readings served as basal test conditions for comparison against readings in dynamic conditions. The average area of sway
Table 2 Range of calculated COP per foot for each subject and the average area of distribution, in static condition for EC conditions. Sub
Left EO ML
F1 F2 F7 F6 F5 F3 F4 F8 F9 M2 M1 M5 M6 M7 M3 M8 M4 M9
2.50 3.63 3.39 4.59 4.04 4.20 4.71 5.03 5.30 3.71 2.66 4.27 3.74 3.35 3.80 3.32 4.50 6.56
AP
0.008 0.066 0.054 0.018 0.073 0.012 0.066 0.018 0.020 0.027 0.006 0.057 0.037 0.087 0.059 0.116 0.445 0.386
Area(mm2)
Right EO
7.16 5.98 5.98 6.43 6.98 7.56 8.07 7.61 9.20 5.88 7.63 5.82 6.03 5.94 6.58 6.55 7.53 6.09
ML
0.019 0.042 0.098 0.040 0.244 0.025 0.091 0.148 0.067 0.021 0.011 0.050 0.027 0.087 0.058 0.184 0.045 0.074
8.87 9.50 9.28 10.00 9.25 8.76 9.74 9.80 9.18 8.76 9.53 9.32 9.68 9.06 9.49 9.48 9.63 9.34
AP
0.018 0.037 0.049 0.020 0.034 0.010 0.080 0.190 0.116 0.010 0.032 0.011 0.017 0.017 0.038 0.015 0.071 0.017
6.22 5.51 5.37 5.59 8.00 6.36 6.32 6.23 5.94 5.43 6.31 4.95 6.74 4.46 5.70 5.92 6.41 5.03
0.026 0.136 0.124 0.606 0.163 0.270 0.335 0.163 0.283 0.012 0.060 0.041 0.241 0.093 0.212 0.102 0.050 0.068
15.57 198.87 290.52 326.84 599.53 705.56 839.10 858.07 871.83 17.76 50.87 83.35 129.76 234.48 293.83 586.44 600.82 764.78
Real-time postural stability measurement system
461
Figure 10 Shift in COP on balance trainer (dynamic condition) for the entire data acquisition (a) Left Foot in EO (b) Right Foot in EO (c) Left Foot in EC (d) Right Foot in EC.
calculated for the subject group in static EO conditions, matches previously published data (Raymakers et al., 2005) for subjects of the same age group (young and healthy). It has been established that humans experience a poorer postural control in absence of a valid visual cue (Kaesler et al., 2007; Siqueira et al., 2009). The platform was able to detect the change in postural sway experienced by the body, in absence of a valid visual cue in static conditions. This was observed in the static condition experiments when subjects recorded a larger distribution area in EC, Table 2, as compared to the EO, Table 1. Analysis on the data from the force sensing platform in static condition was also able to localize the regions of high concentration of the COP. In the EO experiment the distribution sites were observed to be within a single region, Figure 9(a) and (b). However, in the EC experiment there were two major concentration sites in which the calculated COP oscillates within Figure 9(c) and (d). This observation was in parallel with the observation that in absence of a visual cue, subjects become solely reliant on the
proprioceptors to inform the CNS on the body’s position with respect to its surrounding. The proprioceptors now become responsible for informing the CNS when the body is swaying excessively in a certain direction, so that compensatory measures can be made to counter the sway experienced. In the experiments for dynamic condition, subjects recorded a much higher oscillation and larger distribution of COP, for both legs, Figure 10. This was due to the reason that the moveable platform used to emulate dynamic condition tilts in the direction of the nett force exerted on its surface. This tilting to one direction required compensatory measures, which was exerted by the opposite portion of the foot, to maintain ‘neutral’ position (controlled by the CNS). This sway of forward and backward or left to right motion, is the reason for the overall increase in oscillation and distribution area of the COP in dynamic conditions. Despite being distributed over a larger area, the oscillation observed for the EO is centered within a single area Figure 10(a) and (b). The data in Table 3 also identifies that subjects tend to depend on one foot. This
462
A.A. Gopalai et al.
Table 3 Range of calculated COP per foot for each subject and the average area of distribution, in dynamic condition for EO conditions. Sub
Left EO ML
F1 F2 F5 F3 F4 F7 F6 F8 F9 M2 M3 M1 M5 M4 M9 M6 M8 M7
3.69 3.15 3.02 3.46 3.82 3.66 2.87 3.38 3.35 3.45 3.50 4.49 3.76 2.67 3.79 3.35 3.32 3.82
AP
0.033 0.035 0.106 0.110 0.234 0.388 0.172 0.076 0.044 0.129 0.080 0.128 0.035 0.130 0.040 0.152 0.198 0.230
Area(mm2)
Right EO
6.40 6.43 7.46 6.54 7.52 7.28 6.97 6.44 7.06 6.76 6.49 7.77 6.24 6.79 6.12 6.65 7.25 7.28
ML
0.090 0.253 0.055 0.082 0.129 0.061 0.108 0.074 0.031 0.018 0.193 0.058 0.253 0.071 0.269 0.154 0.175 0.242
was observed by a significantly smaller overall distribution of the individual foot area of distribution, which indicates subjects tend to rest their body weight on one foot while trying to compensate for the sway experienced with the opposite foot. In EC for dynamic condition, subjects become heavily reliant on the proprioceptors at the feet, and subjected to significantly higher body sways, Table 4. Unlike the previous observations, there are no clear observable distribution sites in EC for dynamic conditions. Subjects were observed to rest their body weight on a particular foot, as was in EO
9.43 9.75 9.36 10.48 8.95 10.53 9.78 9.62 9.68 9.46 8.85 9.89 9.33 9.02 9.33 9.53 9.53 9.45
AP
0.038 0.023 0.176 0.164 0.089 0.124 0.234 0.566 0.289 0.095 0.030 0.067 0.020 0.036 0.021 0.099 0.084 0.122
6.72 6.60 6.55 6.98 6.78 6.75 6.37 6.67 5.83 6.53 5.97 6.56 7.21 5.88 7.07 6.11 5.57 5.64
0.321 0.390 0.193 0.210 0.177 0.265 0.171 0.173 0.365 0.098 0.056 0.159 0.493 0.351 0.623 0.099 0.068 0.335
386.23 453.25 1017.98 1113.06 1173.04 1450.77 1514.68 2648.73 2731.17 296.14 439.04 460.22 486.31 562.07 610.66 849.74 1028.85 2464.90
for dynamic conditions. This was observed graphically in Figure 10(d) when a particular foot graph of the subject has a smaller concentrated distribution as opposed to the opposing foot in Figure 10(c). Subjects who could not maintain balance and were at the verge of falling due to the lost of balance, came in contact with the safety hand rail. In such cases, the acquisition period was cut short. Portions of the data set after contact with the safety hand rail could no longer be considered valid because it has been corrupted by additional sensory information that was unintended during the data acquisition. Out of the 18
Table 4 Range of calculated COP per foot for each subject and the average area of distribution, in dynamic condition for EC conditions. Sub
Left EO ML
F1 F2 F7 F5 F4 F6 F9 F8 F3 M2 M3 M4 M5 M1 M7 M8 M6 M9
3.69 3.15 3.66 3.02 3.82 2.87 3.35 3.38 3.46 3.45 3.46 2.66 3.76 4.49 3.82 3.32 3.35 2.64
AP
0.315 0.329 0.230 0.237 0.249 0.375 0.232 0.411 0.566 0.122 0.168 0.257 0.089 0.357 0.610 0.386 0.338 0.722
Area(mm2)
Right EO
6.40 6.43 7.27 7.46 7.52 6.97 7.06 6.44 6.54 6.76 6.65 6.79 6.24 7.77 7.28 7.25 6.65 5.72
ML
0.182 0.199 0.277 0.178 0.215 0.267 0.280 0.294 0.245 0.055 0.207 0.085 0.220 0.297 0.212 0.156 0.347 0.181
9.43 9.75 10.53 9.36 8.94 9.78 9.68 9.62 10.05 9.46 8.83 9.02 9.33 9.89 9.45 9.53 9.53 6.75
AP
0.063 0.121 0.142 0.336 0.339 0.260 0.374 0.241 0.573 0.148 0.037 0.154 0.086 0.141 0.120 0.255 0.133 1.937
6.72 6.60 6.75 6.55 6.77 6.37 5.83 6.67 6.98 6.53 5.97 5.88 7.21 6.56 5.64 5.57 6.11 8.13
0.331 0.346 0.399 0.368 0.348 0.314 0.364 0.344 0.369 0.115 0.041 0.126 0.527 0.219 0.206 0.372 0.367 1.517
2000.60 2739.75 3083.48 4249.04 4379.42 4650.31 5144.93 5218.94 8967.69 606.33 926.04 1057.55 1660.04 3506.28 3942.71 3970.52 4237.87 78,580.89
Real-time postural stability measurement system subjects that performed the trial, only 2 subjects found it impossible to maintain balance on the balance trainer in EC.
Conclusion The results obtained demonstrate the force-sensing platform’s ability to test and gauge postural control by means of proprioceptive strength. The research concentrated on the means of monitoring the proprioceptive strength by utilizing the FSR to monitor high pressure concentration sites. The output of the system enables end users to easily identify areas of the subjects’ foot that experiences a high level of forces, in real-time (static and dynamic conditions). The high level of forces within a certain area, indicates the region of the foot that subjects tend to use to balance themselves. Training and feedback helps address and target the identified area in which force concentration takes place during balancing and helps reduce pressure concentration. The outputs from the post-processing procedures provides end-users with a quantitative assessment of the postural control by means of proprioceptive control. Good proprioception is seen as the ability to maintain balance and a relatively constant pressure throughout the surface of both feet. Such features of pressure distribution at the feet is desirable, for a lower risk of foot related injuries. The designed system helps monitor the proprioception at the feet and can be used to identify individuals that begin to demonstrate early signs of balance deterioration. In a clinical setting, balance deterioration would have a different impact for athletes and non-athletes. A balance deterioration to an athlete would mean a drop in performance or an increased probability for sprains and foot related injuries. Deterioration to a non-athlete would indicate an increased risk of falls in daily activity, which could be fatal depending on the age group of the individual. Based on the results obtained, which were in agreement with other literature, the use of the FSR as a basic sensing element to provide quantitative and qualitative measurements of postural control was validated. The method utilized a force-sensing platform to detect the location of the weighted center of applied pressure per data sweep and analyzed the readings acquired with respect to time. The calculated coordinates were used to describe the migration of the weighted centers over time. The presented method to assess balance, was shown to be sensitive to changes in the postural control system and demonstrated itself to be a reliable device to measure proprioceptive strength of individuals. This work can be further expanded to test the effects of individual’s lifestyle or fitness level on postural control, within a similar age group. Further improvements can be introduced to the signal conditioning and switching circuit. The implementation of a micro-controller to replace these circuits will improve the performance of the platform and allow for higher sampling rates to be achieved.
Conflict of interest None.
463
Acknowledgement This work was supported by Monash University, Sunway Campus, The Ministry of Science, Technology and Innovation (MOSTI), Malaysia, and Moves International Fitness.
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464 Clinical Neurophysiology/Electromyography and Motor Control 105 (4), 309e320. Nault, M., Allard, P., Hinse, S., Blanc, R.L., Caron, O., Labelle, H., Sadeghi, H., September 1, 2002. 2002. Relations between standing stability and body posture parameters in adolescent idiopathic scoliosis. Spine 27 (17), 1911e1917 [Miscellaneous article]. Owen, N., Leadbetter, A., Yardley, L., 1998. Relationship between postural control and motion sickness in healthy subjects. Brain Research Bulletin 47 (5), 471e474. Page, P., Jan. 2006. Sensorimotor training: a "global" approach for balance training. Journal of Bodywork and Movement Therapies 10 (1), 77e84. Pascolo, P.B., Carniel, R., Pinese, B., 2009. Human stability in the erect stance: alcohol effects and audio-visual perturbations. Journal of Biomechanics 42 (4), 504e509. Prieto, T., Myklebust, J., Hoffman, R., Lovett, E., Myklebust, B., 1996. Measures of postural steadiness: differences between healthy young and elderly adults. IEEE Transactions on Biomedical Engineering 43 (9), 956e966.
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Journal of Bodywork & Movement Therapies (2011) 15, 465e477
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ULTRASOUND IMAGING
Application of rehabilitative ultrasound in the assessment of low back pain: A literature review Leila Ghamkhar a, Mahnaz Emami a, Mohammad A. Mohseni-Bandpei a,b,*, Hamid Behtash c a Department of Physiotherapy, The University of Social Welfare and Rehabilitation Sciences, Student Boulevard, P.O. Box 1985713834, Evin, Tehran, Iran b Department of Rehabilitation, School of Medicine, Khazar Boulevard, P.O. Box 48168, Sari, Mazandaran, Iran c Department of Spine Surgery, Hazrat Rasoul-e-Akram Teaching Hospital, Iran University of Medical Sciences, Tehran, Iran
Received 12 February 2010; received in revised form 3 July 2010; accepted 7 July 2010
KEYWORDS Low back pain; Ultrasound imaging; Multifidus; Transverse abdominis; Review
Summary Low back pain (LBP) is one of the most common work-related conditions affecting all populations both in industrialized and non-industrialized countries, with reported high prevalence and incidence rates and huge direct and indirect costs. Among various suggested causes of LBP, dysfunction of back muscles, particularly lumbar multifidus and transverse abdominis, has been the subject of considerable research during last decades. Of the available imaging techniques, ultrasound (US) imaging technique is increasingly used to assess muscle dimensions and function as a valid, reliable and non-invasive approach. The purpose of the present study was to review the previously published studies (1990e2009) concerning the merit of US imaging of lumbar and abdominal muscles with particular attention to its clinical application in patients with LBP. Studies showed wide variation in terms of methodology, sample size, procedure, definition of LBP, heterogeneous sample, method of analyzing US imaging, US imaging parameters, etc. However, a convincing body of evidence was identified that supports US imaging as a reliable and valid tool both to differentiate patients with LBP from normal subjects and to monitor the effect of rehabilitation programs. ª 2010 Elsevier Ltd. All rights reserved.
* Corresponding author. Department of Physiotherapy, The University of Social Welfare and Rehabilitation Sciences, Student Boulevard, P.O. Box 1985713834, Evin, Tehran, Iran. E-mail address:
[email protected] (M.A. Mohseni-Bandpei). 1360-8592/$ - see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.07.003
466
Introduction Low back pain (LBP) is one of the most prevalent workrelated conditions affecting all populations both in industrialized and non-industrialized countries (Jin et al., 2004; Mohseni-Bandpei et al., 2006, 2007). It is the fifth most common reason for all visits to physicians in the United States (Hart et al., 1995). Approximately one quarter of adults in the United States reported having LBP lasting at least one day in the past 3 months (Deyo et al., 2006). A high prevalence rate and associated economic and social costs have been reported due to LBP in France (Gourmelen et al., 2007). In Iran, a lifetime prevalence of LBP in the nursing population and pregnant women was reported to be 62% and 84%, respectively (Mohseni-Bandpei et al., 2006, 2009) associated with 33.7% of work absenteeism during the past month in nurses (Mohseni-Bandpei et al., 2006). In the United States the total incremental direct health care costs attributable to LBP were estimated to be $26.3 billion in 1998 (Luo et al., 2004). In addition, indirect costs related to days lost from work were substantial, with approximately 2% of the United States work force compensated for back injuries each year (Andersson, 1999). Although indirect costs may be mainly borne by the corresponding social insurance institutions, a significant financial burden can still be imposed on the patients. The costs have been estimated to be 0.7% of Gross Domestic Product (GDP) in Sweden and 1.7% of GDP in the Netherlands (Ekman et al., 2005). A German cost-of-illness study estimated total costs of back pain at around V17 billion, equating to 0.9% of the GDP (Wenig et al., 2009). Dysfunction of the back muscles has been a focus of many studies. The muscles in the lower back area are divided into two groups: global and local (Bergmark, 1989). Some research has demonstrated that there are altered activation patterns of the trunk muscles as they relate to the concept of spinal stability (Cresswell et al., 1992, 1994; Hodges and Richardson, 1996). In healthy subjects, it is suggested that the transverse abdominis (TrA) is the first muscle to be activated and contracted before limb movement, regardless of the direction of motion (Hodges and Richardson, 1996). In individuals with LBP, the contraction of the TrA are reported to be significantly delayed and to follow direction-specific patterns, indicating a potential for decreased spinal stability and fundamental problems with motor control (Hodges and Richardson, 1997, 1998). Several studies have identified significant ipsilateral muscle atrophy of lumbar multifidus (MF) in individuals with unilateral LBP compared with healthy subjects (Hides et al., 1994, 1995, 1996). It was reported by Panjabi (1992) that MF and TrA have a greater role than other muscles in lumbar stability and showed a more decreased cross-sectional area (CSA) in chronic LBP patients (Akbari et al., 2008; Hides et al., 2008a; Mannion et al., 2008). Therapeutic exercises have been developed for individuals with LBP over time. Recently, there has been an emphasis on a specific type of exercise that aims to restore stability in the lumbar spine (Richardson and Jull, 1995; Wilke et al., 1995; Cholewicki and McGill, 1996). It is believed that the mechanism for pain relief with this specific type of exercise is
L. Ghamkhar et al. through enhanced stability of the lumbar spine segments (Richardson and Jull, 1995). Several muscles are targeted, particularly the TrA, lumbar MF, and other paraspinal, abdominal, diaphragmatic, and pelvic floor musculature. Given the widespread clinical use of lumbar stabilization exercise, it is necessary to critically assess the evidence of their efficacy in patients with chronic LBP (O’Sullivan et al., 1997; Koumantakis et al., 2005; Cairns et al., 2006; Goldby et al., 2006; Ferreira et al., 2007). Among various imaging techniques, such as magnetic resonance imaging (MRI) and computerized tomography (CT) scanning, US imaging which involves sending short pulses of US into the body and using reflections received from tissue interfaces to produce images of internal structures, has been developed during the past 50 years with widespread application in medicine, particularly in gynaecology and obstetrics, internal medicine, surgery, orthopaedics, neurology and paediatrics. The application and usefulness of US in the field of musculoskeletal system has been demonstrated in many studies (i.e., Harcke et al., 1988; Kaplan et al., 1990; van Holsbeeck and Introcaso, 1992; Chhem et al., 1994). US has also been used as a direct assessment of atrophy and hypertrophy of different muscles (e.g., Stokes and Young, 1986; Hides et al., 1992; Hides et al., 1994; Stokes et al., 2007) as well as in evaluation of the efficacy of the rehabilitation programs (e.g., Hides et al., 1996; Teyhen et al., 2005; Raney et al., 2007). Despite the high image resolution provided by CT and MRI techniques and high dependency of US imaging on the expertise of the operator, US imaging was found preferable to other imaging techniques because of low examination costs, lack of exposure to ionizing radiation and ready availability (Chhem et al., 1994; Hides et al., 1998). The reliability and validity of new diagnostic procedures are important issues to consider with respect to clinical application. Reliability is the extent to which the repeated measurements of a technique by different people and instruments, at different times and places get similar results. Validity refers to the instrument’s capability to measure what it was intended to measure (Domholdt, 2005). The reliability and validity of measurement of muscle size using US imaging have been investigated in different muscles and found to be a reliable (Stokes and Young, 1986; Martinson and Stokes, 1991; Hides et al., 1992) and a valid (Sipila and Suominen, 1993: Hides et al., 1995) technique. However, they suffer some methodological flaws. Two aspects of muscle function that can be assessed using imaging techniques are muscle size and muscle contraction. The clinical relevance of these techniques is that they allow documentation of morphology and dynamic muscle function in both healthy subjects and those with acute and chronic LBP. Detection of changes in MF and TrA muscle size and motor control in people with LBP compared with healthy subjects may provide valuable information which can be used to guide rehabilitation approaches (Stokes and Young, 1986; Martinson and Stokes, 1991; Hides et al., 1992, 1994, 1995; Sipila and Suominen, 1993; Hodges and Richardson, 1996, 1998; Hodges et al., 2003) The method of choice for recording anticipatory muscle activity has been intramuscular electromyography (EMG) (Danneels et al., 2002; Moseley et al., 2002; Mohseni-Bandpei et al., 2000; Vasseljen et al., 2006).
Review: Application of rehabilitative ultrasound in the assessment of low back pain Although EMG seems to be a superior method in small experiments confined to the laboratory, the complexity and discomfort of this invasive method may not be well suited for large clinical trials. If muscular timing discrepancies in LBP patients are proved to consistently correlate to pain status, there is a need for a more practical recording method than intramuscular EMG in clinical settings. One such method could be US imaging applied in motion-mode (M-mode), where an image of muscle tissue deformation is updated several hundred times a second (Vasseljen et al., 2006). A number of studies have been carried out to investigate local muscles activity, and to attempt to differentiate LBP patients from normal subjects using US, with contradictory findings (Hides et al., 1994; Lee et al., 2006; Hides et al., 2007a; Kiesel et al., 2007a; Akbari et al., 2008; Kiesel et al., 2008). The aim of the present study was to review the previously published studies (1990e2009) concerning the merit of US imaging of lumbar and abdominal muscles, with particular attention to its clinical application in monitoring progress of patients with chronic LBP undergoing rehabilitation programs.
Methods A literature search for the period 1990e2009 was conducted, using PubMed, ProQuest, Science Direct, Thomson, EMBASE, OVID, CINAHL and MEDLINE databases. The following keywords were used: Ultrasonography, Ultrasound imaging, Low back pain, Back muscles, Multifidus, Transverse abdominis, Muscle size, Reliability and Validity. In addition, references given in relevant publications were also used. Studies were required to meet the following criteria: 1. an empirical study design employing US imaging; 2. spinal or abdominal muscles (i.e., multifidus, transverse abdominis, .) were measured; 3. human subjects were studied, both normal subjects and patients with LBP and 4. the article was a full report published in a peer reviewed journal in the English language. If no abstract was present, or if, based on title and abstract, it was not clear whether an article should be included, the whole article was checked. Articles were included if they met all these four inclusion criteria. Two reviewers (LG and ME) read all the abstracts, and the third and fourth reviewers (MAMB and HB) separately have read a random sample of the abstracts. A consensus meeting was arranged to reach agreement on any differences between all reviewers. Finally, a snowball search was carried out, in which reference lists of the selected articles were checked for which titles including US and LBP. The outcome of a study was identified as “positive” if the authors concluded there was a difference in muscle size recorded by US imaging between LBP and normal subjects or in a specific group or particular condition of the study population. The outcome of a study was classified as “negative” if the authors concluded that there was no difference in muscle size between LBP and normal subjects as measured by US imaging. These definitions of the “positive” and “negative” are used throughout this paper.
467
Results The literature search yielded 178 articles using the above keywords. The inclusion criteria were met by 36 articles (Hides et al., 1992; Kennelly and Stokes, 1993; Hides et al., 1994, 1995, 1996; Eisele et al., 1998; Bunce et al., 2002; Critchley and Coutts, 2002; Coldron et al., 2003; Hodges et al., 2003; Ferreira et al., 2004; McMeeken et al., 2004; Watanabe et al., 2004; Stokes et al., 2005; Teyhen et al., 2005; Ainscough-Potts et al., 2006; Hides et al., 2006; Lee et al., 2006; Pressler et al., 2006; Rankin et al., 2006; Springer et al., 2006; Vasseljen et al., 2006; Hides et al., 2007a, 2007b; Kiesel et al., 2007a, 2007b; Norasteh et al., 2007; Raney et al., 2007; Wallwork et al., 2007; Akbari et al., 2008; Hides et al., 2008a, 2008b; Kiesel et al., 2008; Mannion et al., 2008; Koppenhaver et al., 2009; Wallwork et al., 2009). Table 1 provides details of the studies in chronological order from 1990 to March 2009. The most important reasons for exclusion were the article was not in English language; Lumbar and abdominal muscles were not assessed; an US imaging technique was not used. In all studies, the authors reported differences in US imaging measures recorded in LBP subjects compared with normal, or within the various diagnostic subgroups of LBP; when tested in one, or more postural positions or when a relationship was found, compared with a gold standard (e.g., MRI). Of the 36 studies, 9 monitored rehabilitation programs, including stabilization exercises, manipulation, traction, abdominal hollowing exercises, abdominal draw-in maneuvers, motor control exercises, and general exercises (Hides et al., 1996; Critchley and Coutts, 2002; Teyhen et al., 2005; Kiesel et al., 2007b; Raney et al., 2007; Akbari et al., 2008; Hides et al., 2008b; Kiesel et al., 2008; Mannion et al., 2008). All studies reported positive results in US imaging parameters after rehabilitation programs (Table 2). Fourteen studies of the 36 studies selected (Hides et al., 1992; Kennelly and Stokes, 1993; Hides et al., 1994; Eisele et al., 1998; Coldron et al., 2003; Watanabe et al., 2004; Stokes et al., 2005; Ainscough-Potts et al., 2006; Lee et al., 2006; Rankin et al., 2006; Springer et al., 2006; Hides et al., 2007b; Hides et al., 2008a; Wallwork et al., 2009), investigated muscle dimensions in different positions in healthy subjects or correctly identified patients with LBP from normal subjects based on US imaging findings. Only one study tried to identify the relationship between pain intensity and US imaging findings and in which no relationship was found between these two variables. Table 3 provides details of studies in which muscle size was measured in both healthy subjects and patient population using US. Nine of the 36 studies (Bunce et al., 2002; McMeeken et al., 2004; Watanabe et al., 2004; Teyhen et al., 2005; Pressler et al., 2006; Hides et al., 2007a; Norasteh et al., 2007; Wallwork et al., 2007; Koppenhaver et al., 2009) specifically looked at the reliability of employing US imaging on patients, normal subjects, or both and seven studies (Hides et al., 1995; Hodges et al., 2003; Ferreira et al., 2004; McMeeken et al., 2004; Hides et al., 2006; Vasseljen et al., 2006; Kiesel et al., 2007a) investigated the validity of US imaging. Tables 4 and 5 provide details of studies investigating the reliability and validity of US in the assessment of different muscles.
468
Table 1
Details of trials evaluating lumbar and abdominal muscles using US imaging in LBP. Subjects (numbers)
Measuring items (muscle)
Intervention/position
Conclusion
Hides et al. (1992)
NLBP (48)
CSA (MF)
Right and left sides and also between males and females
Kennelly and Stokes (1993)
Adolescent idiopathic scoliosis (20) ALBP (26), NLBP (51)
CSA (MF)
Right and left sides of the curve
CSA (MF)
The effect of LBP on muscle size
Hides et al. (1995)
NLBP (10)
Thickness (MF)
To compare MRI findings with US imaging
Hides et al. (1996)
LBP (39)
Thickness (MF)
Medical treatment and specific localized exe.
Eisele et al. (1998)
CSA (Paraspinal)
To investigate the change of the ultrasonic texture of the paraspinal lumbar muscle
Critchley and Coutts (2002) Bunce et al. (2002)
A Z NLBP (30), B Z discopathy (20), C Z LBP (40) CLBP (20), NLBP (24) NLBP (22)
Positive. CSA of MF was symmetrical between right and left sides. Muscle shape differed between the males and females Positive. A significant difference was found in CSA of lumbar MF between the two sides of curve Positive. A significant difference was found in CSA of MF between-side and between the two groups at one level Positive. Muscle size could be recorded by US imaging Positive. Muscle recovery was more rapid and more complete in favor of exercise group Positive. A significant difference was found in muscle size among three groups
Thickness (abdominal) Thickness (TrA)
Hollowing in four-point kneeling
Coldron et al. (2003)
NLBP (20)
Thickness (MF)
Hodges et al. (2003) (31)
NLBP (13)
Thickness (TrA, IO, EO, TAnt, Br, Bi)
Isometric DF, isometric elbow flex. Intraabdominal pressure
Watanabe et al. (2004)
NLBP (30)
Thickness (ES)
Ferreira et al. (2004)
CLBP (10), NLBP (10)
Thickness (TrA, IO, IE)
Three different positions: maximum flexion, neutral position, maximum extension US imaging was compared with EMG findings
McMeeken et al. (2004)
NLBP (9), NLBP (13)
Thickness (TrA) and EMG activity
US imaging was compared with EMG findings
Stokes et al. (2005)
NLBP (120)
Thickness (MF)
Normal reference data for multifidus size
Hides et al. (1994)
Different positions (supine, standing, walking) Different positions (prone, side lying)
Positive. A significant difference was found between the two groups after treatment Positive. US was found to be a reliable tool to assess the TrA size Positive. No significant difference was found in muscle size in different positions Positive. US imaging can be used to detect low levels of muscle activity but cannot discriminate between moderate and strong contractions Positive. A significant difference was found in ES thickness in different positions Positive. A relationship was found between the presence of LBP and asymmetry of muscle size using US imaging and EMG Positive. A significant correlation was found between US imaging and EMG activity. US was also found to be a reliable tool in measuring muscle thickness Positive. Normal references ranges reported for lumbar multifidus but no clinically significant correlation was found between CSA and anthropometric measures
L. Ghamkhar et al.
Author (year)
Thickness (TrA)
Traditional training and traditional training combined with biofeedback
Ainscough-Potts et al. (2006)
NLBP (30)
Thickness (TrA, IO)
Different positions (supine lying and different sitting positions)
Pressler et al. (2006)
NLBP (30)
Thickness (MF)
Right and left sides of multifidus
Rankin et al. (2006)
NLBP (123)
Thickness (IO, IE, TrA, RA)
Normal reference data for abdominal muscle size
Springer et al. (2006)
NLBP (32)
Thickness (lateral abdominal)
Different positions (rest and while performed ADIM)
Vasseljen et al. (2006)
NLBP (10)
Activity onset (MF)
US imaging was compared with EMG findings
Hides et al. (2006)
NLBP (13)
Thickness (TrA, IO)
US imaging was compared with MRI findings
Lee et al. (2006)
CLBP (16), NLBP (19)
CSA (MF)
Hides et al. (2007a)
NLBP (19)
Thickness (TrA, IO)
Different positions (prone lying, upright standing, and 25 and 45 forward stooping) ADIM in a supine hook-lying position
Hides et al. (2007b)
NLBP (19)
Thickness (TrA, IO)
Static unilateral weight-bearing
Kiesel et al. (2007a)
NLBP (5)
Thickness (MF)
US imaging was compared with EMG findings
Kiesel et al. (2007b)
LBP (56), NLBP (20)
Thickness (TrA, MF)
Raney et al. (2007)
ALBP (9)
Thickness (abdominal)
Stabilization, mobilization, direction-specific exe., traction Spinal manipulation
Norasteh et al. (2007)
ALBP (12), NLBP (27)
Thickness (TrA, IO, EO, RA)
During expiration and inspiration in different positions
Wallwork et al. (2007)
NLBP (10)
Thickness (MF)
Different assessors
Akbari et al. (2008)
CLBP (49)
Thickness (TrA, MF)
Motor control exe. and general exe.
Positive. On average, patients in both groups demonstrated a 2-fold increase in the thickness of the TrA Positive. Muscle thickness could be measured and compared in different positions Positive. US was found to be a reliable tool with reasonable between days intra-rater reliability Positive. The pattern of relative muscle thickness was RA > IO > EO > TrA, but no significant difference was found in muscles between the left and right sides Positive. No differences in the thicknesses of TrA muscle were measured during rest or while contracted, based on hand dominance Positive. US imaging can detect onset of muscle activity comparably accurate to intramuscular EMG Positive. US imaging was correlated with MRI findings in measuring thickness of both TrA and IO muscles Positive. A significant difference was found on CSA of MF in different positions Positive. High reliability of a novice rater was demonstrated for some measurement conditions Positive. A significant increase was found in TrA muscle size during static task Positive. Measuring MF muscle thickness using US imaging was highly correlated with EMG activity of MF in asymptornatic subjects Positive. A significant difference was found in muscle size after intervention Positive. Short-term changes in lateral abdominal muscles thickness was recorded post-spinal manipulation Positive. US was found to be a reliable tool for both symptomatic and asymptomatic subjects. Positive. US was found to be a reliable tool for measuring muscle size Positive. A significant difference was found in muscle size after intervention (continued on next page)
469
LBP (30)
Review: Application of rehabilitative ultrasound in the assessment of low back pain
Teyhen et al. (2005)
NLBP (30) Koppenhaver et al. (2009)
LBP Z low back pain, CLBP Z chronic low back pain, ALBP Z acute low back pain, NLBP Z non-low back pain, MF Z multifidus, TrA Z transverse abdominis, IO Z internal oblique, EO Z external oblique, RA Z rectus abdominis, exe Z exercise, CSA Z cross-sectional area, ES Z erector spinae, US Z ultrasonography, PF Z pelvic floor, TAnt Z tibilialis anterior, Br Z brachialis, Bi Z biceps brachii, ADIM Z abdominal draw-in maneuver, BMI Z body mass index, DF Z dorsi flexion, Flex Z flexion.
During rest and contraction
Abdominal hallowing exe. in hook-lying CLBP (14), NLBP (14) Mannion et al. (2008)
Thickness (TrA, IO, EO) Thickness (TrA, MF)
During rest and contraction CLBP (17), NLBP (17) Wallwork et al. (2009)
CSA (MF)
5% hypertonic saline was injected into Longissimus muscle Thickness (TrA, MF) Kiesel et al. (2008)
Elite cricketers with and without LBP (21) NLBP (6) Hides et al. (2008b)
CSA (MF)
Staged stabilization training
Positive. A significant difference was found in multifidus muscle size and symmetry between NLB and patients with CLBP Positive. A significant difference was found in muscle size after intervention Positive. US imaging can be used to measure pain-related changes in deep trunk muscle activation Positive. A significant reduction in CSA of MF was found in CLBP group at L5 only Positive. A significant difference was found in both groups after intervention Positive. US was found to be highly reliable for intra-rater and adequately reliable for inter-raters measurements Comparing NLBP with CLBP NLBP (40), CLBP(50) Hides et al. (2008a)
CSA and symmetry (MF)
Subjects (numbers) Author (year)
Table 1 (continued)
Measuring items (muscle)
Conclusion
L. Ghamkhar et al.
Intervention/position
470
Discussion Thirty-six studies employing US imaging in patients with chronic LBP and healthy subjects were reviewed. To the knowledge of the authors, the present review is the first to report on the application of rehabilitative US in the assessment patients with LBP, to measure the muscle size and function in patients with LBP compared with normal subjects, to compare muscle size and function in different conditions and to monitor the effect of rehabilitation programs. This review considered only English language studies. Although this limitation is common in systematic reviews, the possibility of a language bias should be considered. In all currently reviewed studies, the authors reported positive results, which indicate that US imaging is a useful, reliable and valid method in evaluating lumbar and abdominal muscles thickness. Of those nine studies investigating the reliability and the seven studies which investigated validity of US imaging in LBP or normal population, all reported favorable results. Methodological flaws were found in some studies. The most important flaws were use of small sample size; lack of a common definition for LBP; study designs which combined various diagnostic subgroups of chronic LBP; lack of a standardized method of analyzing US imaging; lack of a reliable US imaging parameters; interindividual variability in terms of physical fitness, gender, age, etc. (heterogeneous sample). However, the results of this review show support and evidence to the application of US imaging in the field of rehabilitation.
Monitoring rehabilitation programs As indicated in Table 2, 9 of the studies were carried out to determine the sensitivity of US imaging measurements in monitoring therapeutic interventions such as exercise, manipulation, mobilization, traction. For example, Hides et al. (2008b) have investigated the effect of a staged stabilization training program on CSA of the lumbar MF using US imaging. They measured CSA of the MF at the start and at the completion of a 13-week cricket training camp in 4 elite cricketers with and without LBP. The stabilization program involved voluntary contraction of the MF, TrA, and pelvic floor muscles that progressed from non-weight-bearing to weight-bearing positions and movement training. Pain was also measured on visual analog scale in those with LBP. They demonstrated that improvement in CSA of MF following specific retraining can be detected using US imaging and this was concomitant with a decrease in pain intensity. Mannion et al. (2008) measured thickness of TrA muscle at baseline and after performing abdominal hollowing exercises in hook-lying on normal subjects (n Z 14) and patients with chronic LBP (n Z 14). Changes in the thickness of TrA indicated that patients showed improvement in muscle dimensions following rehabilitation programs. Akbari et al. (2008) compared the effect of motor control exercises with general exercises on 49 patients with chronic LBP who were randomly assigned into either a motor control (n Z 25) or a general exercises group (n Z 24). They assessed the thickness of MF and TrA using US imaging, pain on visual analog scale and activity limitation through Back Performance Scale before and after
LBP Z low back pain, CLBP Z chronic low back pain, NLBP Z non-low back pain, MF Z multifidus, TrA Z transverse abdominis, IO Z internal oblique, EO Z external oblique, PF Z pelvic floor, exe Z exercise, CSA Z cross-sectional area, ADIM Z abdominal draw-in maneuver, BMI Z body mass index.
Motor control exe. and general exe.
Elite cricketers with and without LBP (21) CLBP (49) Hides et al. (2008b)
Thickness (lumbar local stabilizing muscle)
CLBP (14), NLBP (14) Mannion et al. (2008)
Akbari et al. (2008)
NLBP (6) Kiesel et al. (2008)
CSA (MF)
LBP (56), NLBP (20) Kiesel et al. (2007b)
Thickness (TrA, MF)
ALBP (9) Raney et al. (2007)
Thickness (TrA, MF)
Thickness (TrA) LBP (30)
Thickness (abdominal)
Thickness (abdominal) CLBP (20), NLBP (24)
Critchley and Coutts (2002) Teyhen et al. (2005)
Thickness (TrA, IO, EO)
Stabilization, mobilization, direction-specific exe, traction 5% hypertonic saline was injected into longissimus muscle Abdominal hallowing exe. in hook-lying Staged stabilization training
Positive. Muscle recovery was more rapid and more complete in favor of exercise group Positive. A significant difference was found between the two groups after treatment Positive. On average, patients in both groups demonstrated a 2-fold increase in the thickness of the TrA Positive. Short-term changes in lateral abdominal muscles thickness was recorded post-spinal manipulation Positive. A significant difference was found in muscle size after intervention Positive. US imaging can be used to measure pain-related changes in deep trunk muscle activation Positive. A significant difference was found in both groups after intervention Positive. A significant difference was found in muscle size after intervention Positive. A significant difference was found in muscle size after intervention Thickness (MF) LBP (39) Hides et al. (1996)
Medical treatment and specific localized exe. Hollowing exe. in four-point kneeling Traditional training and traditional training combined with biofeedback Spinal manipulation
Intervention Measuring items (muscle) Subject (number) Author
Table 2
Details of trials in which the effect of different interventions was monitored using US.
Conclusion
Review: Application of rehabilitative ultrasound in the assessment of low back pain
471
intervention. A 16-session exercise program of 30 min per session was performed by both groups twice per week for 8 weeks. They concluded that the motor control and general exercises both decreased pain intensity and increased the thickness of TrA and MF as well as lumbar mobility in patients with chronic LBP without any signs of spinal instability. The motor control exercises were more effective than general exercises only in reducing pain intensity. Despite differences in the study sample sizes, selected populations, subcategories of LBP patients, and muscles tested, all studies could be classified as positive. The results of this review therefore indicate that US imaging can be clinically used to evaluate the effect of rehabilitation programs in patients with chronic LBP.
Reliability As it is shown in Table 4, nine studies were conducted to assess the reliability of measuring the CSA of MF and abdominal muscles using US imaging. Images were taken in different static and/or dynamic conditions. Static testing involves US imaging during rest position such as supine or prone position, whereas dynamic testing requires subjects to perform a specific movement. Some studies were carried out on healthy subjects. For example, Bunce et al. (2002) assessed average US imaging values of TrA muscle thickness in different positions. Twenty-two healthy subjects (10 men, 12 women), aged 18e44 years old were imaged in supine, standing, and treadmill walking at 3 kph. The mean thickness for TrA muscle was demonstrated to be larger during standing and walking than in supine in 20 out of the 22 volunteers and it was larger in males compared with females in all three positions. The intraclass correlation coefficients (ICCs) were high for TrA muscle thickness in all three positions. They concluded that the application of M-mode US is a reliable method of measuring TrA in supine, standing, and walking positions when comparing images on separate occasions. Between days reliability becomes an important factor when US imaging is to be used to assess the effect of rehabilitation programs. Quite a few studies have investigated the between days reliability of US imaging in MF and TrA muscles. Only three studies investigated the between days reliability in healthy subjects (McMeeken et al., 2004; Pressler et al., 2006; Koppenhaver et al., 2009). McMeeken et al. (2004) examined the intra-rater reliability of measuring the thickness of TrA muscle in 13 healthy subjects, on two separate days, in supine position when the muscle was relaxed and contracted, using US imaging. They reported high between days reliability with ICC Z 0.989 for B mode and ICC Z 0.981 for M-mode. In the study of Wallwork et al. (2007), the intra and inter-rater reliability were assessed on 10 subjects without a history of LBP at the L2e3 and L4e5 levels. The measurements were carried out three times at each level by two different assessors (one experienced and one novice). They reported high intra-rater reliability with ICC Z 0.96 and 0.97 at the L2e3 and L4e5 levels, respectively and high inter-rater reliability with ICC Z 0.85 and 0.87 at the L2e3 and L4e5 levels, respectively. Finally, they concluded that a novice and an experienced assessor were both able to reliably measure muscle thickness at rest on two different vertebral levels using real-time US imaging.
Details of trials in which the muscles’ size was measured using US in both healthy subjects and patients with LBP.
Author
Subject (number)
Measuring items (muscle)
Intervention/position
Conclusion
Hides et al. (1992)
NLBP (48)
CSA (MF)
Right and left sides and also between males and females
Kennelly and Stokes (1993) Hides et al. (1994)
Adolescent idiopathic scoliosis (20) ALBP (26), NLBP (51)
CSA (MF)
Right and left sides of the curve
CSA (MF)
The effect of LBP on muscle size
Eisele et al. (1998)
CSA (paraspinal)
Coldron et al. (2003)
A Z NLBP (30) , B Z discopathy (20) , C Z LBP (40) NLBP (20)
Thickness (MF)
To investigate the change of the ultrasonic texture of the paraspinal lumbar muscle Different positions (prone, side lying)
Positive. CSA of MF was symmetrical between right and left sides. Muscle shape differed between the males and females Positive. A significant difference was found in CSA of lumbar MF between the two sides of curve Positive. A significant difference was found in CSA of MF between-side and between the two groups at one level Positive. A significant difference was found in muscle size among three groups
Watanabe et al. (2004)
NLBP (30)
Thickness (ES)
Stokes et al. (2005)
NLBP (120)
Thickness (MF)
Ainscough-Potts et al. (2006)
NLBP (30)
Thickness (TrA, IO)
Different positions (supine lying and different sitting positions)
Lee et al. (2006)
CLBP (16), NLBP (19)
CSA (MF)
Rankin et al. (2006)
NLBP (123)
Thickness (IO, IE, TrA, RA)
Different positions (prone lying, upright standing, and 25 and 45 forward stooping) Normal reference data for abdominal muscle size
Springer et al. (2006)
NLBP (32)
Thickness (lateral abdominal)
Different positions (rest and while performed ADIM)
Hides et al. (2007b)
NLBP (19)
Thickness (TrA, IO)
Static unilateral weight-bearing
Hides et al. (2008a)
NLBP (40), CLBP (50)
CSA and symmetry (MF)
Comparing NLBP with CLBP
Wallwork et al. (2009)
CLBP (17), NLBP (17)
CSA (MF)
During rest and contraction
Three different positions: maximum flexion, neutral position, maximum extension Normal reference data for multifidus size
472
Table 3
Positive. No significant difference was found in muscle size in different positions Positive. A significant difference was found in ES thickness in different positions Positive. Normal references ranges reported for lumbar multifidus but no clinically significant correlation was found between CSA and anthropometric measures Positive. No differences in the thicknesses of TrA muscle were measured during rest or while contracted, based on hand dominance Positive. A significant difference was found on CSA of MF in different positions
LBP Z low back pain, ALBP Z acute low back pain, CLBP Z chronic low back pain, NLBP Z non-low back pain, CSA Z cross-sectional area, exe. Z exercise, TrA Z transverse abdominis, MF Z multifidus.
L. Ghamkhar et al.
Positive. The pattern of relative muscle thickness was RA > IO > EO > TrA, but no significant difference was found in muscles between the left and right sides Positive. Asymmetry in the lateral abdominal muscles was found in patients with LBP compared with those without LBP Positive. A significant increase was found in TrA muscle size during static task Positive. A significant difference was found in multifidus muscle size and symmetry between NLB and patients with CLBP Positive. A significant reduction in CSA of MF was found in CLBP group at L5 only.
Review: Application of rehabilitative ultrasound in the assessment of low back pain Table 4
473
Details of trials investigating the reliability of US imaging assessment of low back muscle.
Author
Subject (number)
Measuring items (muscle)
Conclusion
Bunce et al. (2002)
NLBP (22)
Thickness (TrA)
McMeeken et al. (2004)
NLBP (9), NLBP (13)
Thickness (TrA)
Watanabe et al. (2004)
NLBP (30)
Thickness (ES)
Teyhen et al. (2005)
LBP (30)
Pressler et al. (2006)
NLBP (30)
Thickness (lateral abdominal) Thickness (MF)
Hides et al. (2007a)
NLBP (19)
Thickness (TrA, IO)
Wallwork et al. (2007)
NLBP (10)
Thickness (MF)
Norasteh et al. (2007)
ALBP (12), NLBP (27)
Thickness (TrA, IO, EO, RA)
Koppenhaver et al. (2009)
NLBP (30)
Thickness (TrA, MF)
Positive. US was found to be a reliable tool for measuring muscle thickness in different positions (both standing and walking) Positive. High ICC was reported for between days reliability (for B mode and for M-mode). The ICC for between transducer reliability was also reported to be high Positive. Sufficient intra-observer and inter-observer reproducibility was found for US imaging in measuring thickness of ES muscles Positive. A high intra-rater reliability of measuring lateral abdominal muscle thickness was achieved Positive. The high between days inter-rater reliability was reported for the right and left sides of multifidus at S1 level Positive. High reliability of a novice rater was demonstrated for some measurement conditions Positive. US was found to be a reliable tool for measuring muscle size. There was no systematic difference in muscle size measured across operators in the measurement of thicknesses at the L2e3 and at the L4e5 vertebral level Positive. US was found to be a reliable tool for measuring muscle thickness in both symptomatic and asymptomatic subjects Positive. US was found to be highly reliable for intra-rater and adequately reliable for inter-raters measurements
ALBP Z acute low back pain, NLBP Z non-low back pain, CSA Z cross-sectional area, exe. Z exercise, IO Z internal oblique, EO Z external oblique, RA Z rectus abdominis, TrA Z transverse abdominis, MF Z multifidus, EMG Z electromagnetic, SEM Z standard error of measurement, ICC Z intra correlation coefficient.
Table 5
Details of trials investigating the validity of US imaging assessment of low back muscle.
Author
Subject (number)
Measuring items (muscle)
Conclusion
Hides et al. (1995)
NLBP (10)
CSA (MF)
Hodges et al. (2003)
NLBP (13)
Architectural parameters (TrA, IO, EI, Ta, Br, Bic)
Ferreira et al. (2004)
LBP (10), NLBP (10)
Thickness (TrA, IO, EO)
McMeeken et al. (2004) Vasseljen et al. (2006)
NLBP(9), NLBP(13) NLBP (10)
Thickness (TrA) and EMG activity Activity onset (MF)
Hides et al. (2006)
NLBP (13)
Thickness (TrA, IO)
Kiesel et al. (2007a)
NLBP (7)
Thickness (MF)
Positive. Significant correlation was found between CSA measurements using US imaging and MRI Positive. US imaging was correlated with EMG findings in detecting low levels of muscles contractions but no correlation was identified in discriminating between moderate and strong contractions Positive. A relationship was found between the presence of LBP and asymmetry of muscle size using US imaging and EMG Positive. A significant correlation was found between US imaging and EMG activity Positive. M-mode US imaging at high time resolution can detect onset of muscle activity comparably accurate to intramuscular EMG Positive. US imaging was correlated with MRI findings in measuring thickness of both TrA and IO muscles Positive. Measuring MF muscle thickness using US imaging was highly correlated with EMG activity of MF in asymptornatic subjects
LBP Z low back pain, NLBP Z non-low back pain, CLBP Z chronic low back pain, CSA Z cross-sectional area, EMG Z electromyography, US Z ultrasonography, MRI Z magnetic resonance imaging, MF Z multifidus Z , TrA Z transverse abdominis, IO Z internal oblique, EO Z external oblique, T.Ant Z tibilias anterior, Br Z brachialis, Bic Z biceps brachii.
474 Some other studies were carried out on patients with LBP. In a study conducted by Norasteh et al. (2007), 12 patients with acute LBP and 27 normal subjects were selected. Within and between days reliability were tested on abdominal muscles in supine, sitting, and standing positions. They reported that there is high reliability on measuring muscle thickness not only in asymptomatic subjects but also in symptomatic subjects. These results suggest that US imaging in chronic LBP is as reliable as in healthy subjects. Together these results suggest US imaging to be a reliable measures in the assessment of lumbar and abdominal muscles, and acceptable for clinical application, in both LBP and normal populations.
Discriminating chronic LBP subjects from non-LBP Some studies focused onto the discrimination of chronic LBP from normal subjects. Results suggest that there is adequate evidence to support US as a valid instrument to detect muscle delayed activation particularly in MF and TrA in chronic LBP (Hides et al., 1994; Ainscough-Potts et al., 2006; Hides et al., 2007b). For example, Hides et al. (1994) compared CSA of MF in 26 patients with acute LBP (aged 17e46) with 51 normal subjects (aged 19e32). In all patients, CSA was measured from the 2nd to the 5th lumbar vertebrae (L2e5) and in six patients at S1 level. In all normal subjects, CSA was measured at L4 and in 10 subjects measurements were made from L2e5. They found marked asymmetry in CSA of MF in patients with the smaller muscle being on the painful side, but there was no correlation between the degree of asymmetry and severity of symptoms. In another study (Lee et al., 2006), CSA of MF was measured in 35 males to identify subjects who suffered from chronic LBP. US images were taken on both sides at the L4 and L5 levels with the subjects in prone lying, upright standing, and 25 and 45 forward stooping. In the control group, the CSA of MF increased from prone lying to upright standing and then gradually decreased from 25 to 45 forward stooping. A reverse pattern of the CSA changes was recorded in patients with chronic LBP. It was reported that MF contracts maximally at upright standing in the normal group, while maximum contraction of the muscle occurs at 25 forward stooping in the patient group. The role of MF may be altered in the stabilization of the lumbar spine of chronic LBP patients. Wallwork et al. (2009) compared both the CSA and the ability to voluntarily perform an isometric contraction of the MF muscle at four vertebral levels in 34 subjects with and without chronic LBP. Results showed a significantly smaller CSA of the MF muscle for the chronic LBP group compared with the unimpaired group at the L5 vertebral level and significantly smaller percent thickness contraction for the chronic LBP group compared with the control group at the L5 vertebral level. All studies investigating the discrimination between chronic LBP patients and non-LBP using US imaging, reported positive results with relatively high rate of identification.
L. Ghamkhar et al. et al., 2006) compared MRI with US imaging measures and five studies (Hodges et al., 2003; Ferreira et al., 2004; McMeeken et al., 2004; Vasseljen et al., 2006; Kiesel et al., 2007a) compared EMG findings with US imaging. Hides et al. (2006) compared two imaging modalities MRI and US imaging used for measurement of the MF thickness. Ten normal females aged 21e31 years were imaged on two separate days using MRI and US imaging. Bilateral measurements were made at each vertebral level from L2 to S1. For both modalities, a significant difference was demonstrated in the CSA of MF between each vertebral level measured. They indicate that if a strict protocol is adhered to, realtime US imaging can be used to document muscle size in young adults and further studies are required to validate the technique in older subjects and in different conditions. Ferreira et al. (2004) compared US imaging with EMG findings to measure trunk muscle activity on patients with LBP and normal subjects. Ten subjects with recurrent LBP and 10 matched controls were tested during isometric low load tasks with their limbs suspended. Changes in thickness from resting baseline values were obtained for TrA, internal oblique, and external oblique using US imaging. Fine wire EMG was used concurrently. Changes in automatic control of TrA were found in people with LBP and US imaging was considered a feasible non-invasive test of automatic recruitment of the abdominal muscles. Validity studies examined a number of different muscles. For example, three studies were carried out on MF (Hides et al., 1995; Vasseljen et al., 2006; Kiesel et al., 2007a), four studies on TrA (Hodges et al., 2003; Ferreira et al., 2004; McMeeken et al., 2004; Hides et al., 2006). Kiesel et al. (2007a) determined the relationship between thickness changes of the lumbar MF, as measured by US imaging and EMG findings in 7 normal subjects. They concluded that muscle thickness change as measured by US imaging was highly correlated with EMG findings of MF activity in asymptomatic subjects (r Z 79, P < 0.001). Hides et al. (2006) validated the use of real-time US imaging as a measure of the TrA muscle during a drawing-in of the abdominal wall of 13 healthy asymptomatic male elite cricket players aged 21.3 2.1 years. They were imaged using MRI and US. US imaging of muscle thickness of TrA was found to be highly correlated with measures obtained with MRI (ICC ranging from 0.78 to 0.95). In another study carried out by McMeeken et al. (2004) there was a high correlation (r Z 0.87, P < 0.001) of change in thickness of TrA between US imaging and EMG findings. Vesseljen et al. (2006) carried out a study to explore whether high-frame rate M-mode US could measure anticipatory muscle responses in the lumbar MF reliably and comparably accurate to intramuscular EMG. On 10 normal subjects, they found M-mode US imaging at high time resolution can detect onset of muscle activity comparably accurate to intramuscular EMG, but with a small systematic delay. These results indicate that US imaging appears to be a valid measure in the assessment of lumbar muscles, and acceptable for clinical application, in both LBP and normal populations, as all studies reported positive results.
Validity
Conclusion As demonstrated in Table 5, seven studies have evaluated the validity of measuring CSA of MF and abdominal muscles using US imaging. Two studies (Hides et al., 1995; Hides
The purpose of this study was to review literature published from 1990 to 2009 concerning the merits of using US imaging
Review: Application of rehabilitative ultrasound in the assessment of low back pain in the examination of back muscle function. There was a wide variation in methodology, procedures, equipment and muscles tested and variability in sample size, differences in degree and source of LBP patients, the physical fitness of individuals, etc. However, a convincing body of evidence suggests that US imaging is a reliable and valid tool for differentiating LBP patients from normal subjects and monitoring rehabilitation outcome measures. Further research regarding the classification of various subgroups of LBP patients and the identification of individuals at risk of developing LBP is needed.
Acknowledgements The authors acknowledge the University of Social Welfare and Rehabilitation Sciences and also Mazandaran University of Medical Sciences for financial support of this study. They are also grateful to Dr. Barbara Richardson at the School of Allied Health Professions, Faculty of Health, University of East Anglia for her valuable and constructive comments.
Conflict of interest None.
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Journal of Bodywork & Movement Therapies (2011) 15, 478e484
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MUSCLE PHYSIOLOGY STUDY
Influence of heat on fatigue and electromyographic activity of the biceps brachii muscle* Wagner Menna Pereira, MSc a, Luiz Alfredo Braun Ferreira, MSc a, Luciano Pavan Rossi, MSc a, Ivo Ilvan Kerpers, MSc a, ´ Collange Grecco St b, Alderico Rodrigues de Paula Jr, PhD c, Luanda Andre Claudia Santos Oliveira, PhD b,* a
Universidade Estadual do Centro-Oeste, Padre Salvador 875, Guarapuava, PR, 85015-430, Brazil Universidade Nove de Julho, Francisco Matarazzo 612, Sa˜o Paulo, SP, 05001-100, Brazil c Universidade do vale do Paraı´ba, Shishima Hifumi 2911, Sa˜o Jose´ dos Campos, SP, 12244-000, Brazil b
Received 10 February 2011; received in revised form 26 April 2011; accepted 30 April 2011
KEYWORDS Electromyography; Fatigue; Biceps brachii; Heat; Microwave diathermy
Summary Electromyography enables registering muscle activity during contraction and can identify muscle fatigue. In the present study, 30 volunteers between 18 and 30 years of age were submitted to an exertion 1 min of maximal voluntary isometric contraction. The electromyographic signal of the biceps brachii muscle and the strength of the flexor muscles of the elbow were determined before and after the administration of microwave diathermy in order to analyze the influence of heat over the strength of the elbow flexor muscles and fatigue of the biceps brachii. The results demonstrate that the strength of the elbow flexor muscles diminished significantly following the application of heat (p < 0.05). Heat also led to a significant reduction in the electrical activity of the muscle studied. The present study demonstrates that microwave diathermy on the biceps brachii muscle reduces the flexion strength of the elbow as well as signs of muscle fatigue in the biceps. ª 2011 Elsevier Ltd. All rights reserved.
Introduction Since 1940, electromyography has been widely used for the understanding of the functions and dysfunctions of the
muscle system during human movement. This resource has enabled research in diverse areas of interest to physiotherapists (Lariviere et al., 2004; Coelho et al., 2008; Valouchouva ´ and Lewitt, 2009). Electromyography allows
*
Study carried out at the Universidade Estadual do Centro-Oeste (UNICENTRO), Brazil. ´ gua Branca, CEP 05001-100, Sa * Corresponding author. Av. Francisco Matarazzo 612, A ˜o Paulo, SP, Brazil E-mail address:
[email protected] (C.S. Oliveira).
1360-8592/$ - see front matter ª 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2011.04.007
Influence of heat on fatigue and electromyographic activity of the biceps brachii muscle recording electrical signals generated by the depolarization of muscle cell membranes, thereby enabling the determination of muscle activity during contraction, although not providing information on the torque produced by the muscles (Ocarino et al., 2005). Electromyographic activity captured through surface electrodes represents the overall activity of the motor units recruited during muscle contraction (Ferreira et al., 2004). There are numerous applications of electromyography in physiotherapy, such as: the investigation of muscle strategies regarding joint stabilization; the study of stretching techniques used in sports and physiotherapy aimed at greater muscle relaxation; the evaluation of muscle activity during functional activities; the characterization of muscle activity during exercise; the analysis of motor unit firing rate; and the identification of muscle fatigue (Gonc ¸alves, 2006). Muscle fatigue is a failure to maintain a desired level of yield or work during a repetitive or sustained activity (Gonc ¸alves, 2006). According to Santos et al. (2003), muscle fatigue has a multi-factor etiology and its origin and extension depend on the specificity of the exercise, type of muscle fiber involved and degree of physical fitness. Muscle fatigue can be defined as a state reached through prolonged, intensive muscle contraction (Oksa et al., 2002). Studies involving athletes performing prolonged sub-maximal exercise demonstrate that muscle fatigue increases in nearly direct proportion to the depletion rate of muscle glycogen (Lariviere et al., 2004). Muscle fatigue during short-duration maximal exercise is associated to a lack of oxygen and an increased level of blood and muscle lactic acid as well as a parallel increase in the concentration of hydrogen in the exercised muscle (Thompson, 1985). According to De Lucca (1997), the electromyographic signal is an index for the determination of the muscle economy and fatigue is an important factor in the characterization of this pattern of movement and its efficiency. Microwave diathermy is indicated prior to kinesiotherapy techniques. The aim is to increase blood flow, remove byproducts of the inflammatory process and improve the range of motion of joints by diminishing stiffness, increasing the extensibility of collagen fibers and enhancing the elasticity of soft tissues (Thompson, 1985; Mayor, 2009). This is a therapy modality that provides heat to soft tissues in a quite satisfactory manner and is used in the prevention and treatment of musculoskeletal injuries (Mayor, 2009; Watson, 2002). However, despite its widespread use in the physiotherapy setting, there is a lack of scientific studies that evaluate the effectiveness of diathermy, the neuro-physiological characteristics of which, such as intravascular vasodilatation, are difficult to measure. A number of studies stress the use of cold and its influence over electromyography (Coelho et al., 2008; Coulange et al., 2006; Pereira, 2008). Madigan and Pidcoe (2001) investigated the influence of temperature on muscle
Table 1
479
fatigue of the flexor group of the elbow through electromyography, demonstrating that a change in the temperature of the muscle has a direct effect on the fatigue process. Pereira (2008) used ice on the tibialis anterior muscle and demonstrated that the reduction in temperature reduced the isometric strength of the muscle and altered its electrical activity. The aim of the present study was to analyze the influence of microwave diathermy over the strength of the flexor muscles of the elbow and fatigue in the biceps brachii muscle through electromyography in the frequency domain.
Materials and methods Sample Thirty healthy male and female volunteers between 18 and 30 years of age with no clinical history of osteoarticular or musculoarticular pain or injury participated in the present study. All volunteers received information on the procedures and objectives of the study and signed terms of informed consent.
Setting The study was conducted at the Biological Signal Processing Laboratory of the Physiotherapy Teaching Clinic of the Universidade Estadual do Centro-Oeste, located in Guarapuava e PR, Brazil.
Procedures The volunteers were initially submitted to a clinical evaluation (medical history and physical exam) in order to ensure the absence of any abnormality of the neuromuscular-articular system and record the anthropometric data (Table 1). The placement of the electrodes was preceded by shaving and cleaning the skin with alcohol in order to reduce bioimpedance. All volunteers underwent a warm-up period in the form of a 5-min walk in order to increase blood flow and muscle nutrition as well as to avoid injuries. The placement of the electrodes was based on the method described by Delagi and Perotto (1980). The subjects were seated, with head and shoulders in a neutral position, without arm support and an electronic goniometer was placed on the elbow such that the joint was set at precisely 90 of flexion, which is the position in which the strength of the biceps brachii is most effective (Always et al., 1992). The individuals were given a period of adaptation to the electrodes and muscle contraction in an effort to achieve greater efficiency in muscle contraction during the exercise.
Anthropometric characteristics of the sample.
Mean Standard deviation
Age (years)
Height (cm)
Weight (kg)
Body mass index
23 2
171 7
68 11
23 3
480 The volunteers were instructed to contract the biceps brachii muscle with isometric flexion of the elbow and no angular movement. Movement was impeded by a chain connected to a load cell fixed to the floor, which aided in the identification of the electrical impulse of the muscle contraction (Figure 1). Upon hearing the “start” signal, the individuals performed a contraction with maximal biceps strength for 60 s. This procedure was carried out on both arms. According to Thompson (1985), a muscle needs a 20-min rest period for the fibers to reacquire their initial structural state for the performance of further maximal voluntary activity. This period was strictly adhered to and the individuals were then submitted to additional maximal contraction of the biceps brachii on both arms, but with the prior administration of microwave diathermy (heat) for 16 min on the dominant arm. The expected circulatory effects caused by diathermy initiate 12e15 min into treatment (Goats, 1999; Low and Reed, 1994; Mitchell et al., 2008). Although previous studies report that the greatest increase in temperature provided by diathermy occurs 20 min into treatment (Draper et al., 1999; Garrett et al., 2000; Mitchell et al., 2008) and this is the most cited time in the literature (Mitchell et al., 2008; Saga et al., 2008; Nosaka et al., 2007), a time of 16 min was established in the present study, as this was the minimal time required to trigger therapeutic physiological effects. Heat was applied to the belly of the biceps brachii muscle through a circular inductive electrode positioned perpendicular to the muscle. The volunteers were instructed to report the sensation of heat, which was not to reach the point of becoming unpleasant.
Instruments An eight-channel electromyograph (EMG System Brazil Ltda) was used for the acquisition of the electromyographic signal, using active, bipolar, differential surface electrodes, connected to the Windaq signal acquisition software program. A load cell (EMG System) with a capacity to
Figure 1 System for determining electromyographic activity of the biceps brachii muscle.
W.M. Pereira et al. measure traction at an intensity of approximately 200 kgf based on transducer strength was used for the determination of traction strength of the elbow flexor muscle group. Microwaves (EFROM 2.45 G MICROWAVE) were administered for 16 min, with the intensity between 50 and 55% of the maximal intensity of the apparatus. The dosimetry suggested fixed times of 3, 8, 16 and 22 min. Two sample channels were used for the analysis of the signal e one for the load cell (kgf) and the other for muscle activation of the biceps brachii muscle. EMG Works Delsys Analysis software program was used for the acquisition of the raw values and visualization of the signal, with a graph of the signal intensity (y axis) and time (x axis), for which the 60-s data collection unit was divided into three 20-s steps. For each 20-s interval (00e20, 20e40 and 40e60), the root mean square (RMS) and median frequency (MF) values were determined and kgf was used for the quantification of the load cell. RMS values in each time interval were organized in tables separated in control limbs and those submitted to heat, along with the MF and load cell (kgf) values. The BioEstat 4.0 software program was used for the analysis of the statistical data. D’Agostino’s test was used to test the normality of the sample. As the sample demonstrated a normal distribution pattern, the Student’s t-test was used for the comparisons, with the level of significance set at 5% (p 0.05).
Results Figure 2 displays the electromyographic signal of the biceps brachii for 60 s, divided into 20-s intervals. Compared to the first evaluation, there was a reduction in peak electromyographic strength in the control limb at all time intervals (00e20; 20e40 and 40e60), but the difference was only statistically significant in the final 20 s (Figure 3). An analysis of the entire 60 s reveals that initial strength was low, reaching maximal intensity between 20 and 40 s and diminishing thereafter. For the limb treated with heat, there was a significant reduction in strength at all time intervals when compared to the evaluation before the administration of the heat. The same behavior was seen in the analysis of the entire 60 s, with an initially low intensity followed by greater peak muscle strength between 20 and 40 s and a reduction in the final 20 s (Figure 4). Figure 5 illustrates the electrical activity in the control muscle, which was similar throughout the 60 s of maximal contraction. There was a slight increase in activity between evaluations in the second (20e40) and third (40e60) intervals when compared to the initial 20 s, but this difference did not achieve statistical significance. For the heat-treated limb, there was a reduction in electromyographic activity after microwave diathermy in all time intervals when compared to the evaluation before the heat treatment, with statistically significant differences in the 00e20 and 20e40 intervals. There was also a uniform drop in muscle activity in both evaluations of the entire 60 s (Figure 6). The median frequency (MF) in the control limb increased on the second evaluation, but this difference did not achieve statistical significance. On both evaluations, there was
Influence of heat on fatigue and electromyographic activity of the biceps brachii muscle
Figure 2
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Signal sampled for the extraction of the values in different time intervals (00e20, 20e40 and 40e60).
a drop in frequency throughout the entire 60 s of maximal contraction (Figure 7). A similar pattern was found for the heat-treated limb, with an increase in MF between the first and second evaluations and a drop in MF in both evaluations throughout the 60 s of maximal contraction (Figure 8).
Discussion Different muscle groups have been the objects of investigations into muscle fatigue using electromyography (Lariviere et al., 2004; Karlsson et al., 2003; Malachy, 2002). A large number of studies have addressed the biceps brachii muscle in particular (Langenderfer et al., 2005; Ravier et al., 2005; Sbriccoli et al., 2003; Hunter et al., 2003). Seghers and Spaepen (2004) assessed the influence of two exercise protocols on muscle fatigue of the elbow flexor muscles and postulate that muscle fatigue is identified through electromyography by an increase in the
Figure 3 Peak electromyographic strength of control limb (mean standard error); *significant difference in value (kgf) measured by the load cell transducer (p 0.05).
amplitude of the signal and drop in the median frequency (Seghers and Spaepen, 2004). In the present study, there was a drop in MF over the 60 s of data collection, but this drop was not significant. There was a significant reduction in RMS in the heat-treated limb in comparison to the control limb. Silva and Gonc ¸lves (2003) also analyzed signal amplitude and MF for the identification of muscle fatigue and found that the 60-s exertion protocol proved effective for the identification of fatigue. In the present study, an analysis of the electromyographic signal in the frequency domain revealed a reduction in the MF throughout the 60 s of maximal isometric effort. This finding demonstrates muscle fatigue, as the drop in frequency is said to be characteristic of the fatigue process. However, the MF values were higher in the heat-treated muscle when compared to the evaluation prior to the application of the heat as well as when compared to the control muscle. Madigan and Pidcoe (2001) analyzed the influence of a temperature increase on the characteristic of the
Figure 4 Peak electromyographic strength of heat-treated limb (mean standard error); *significant difference in value (kgf) measured by the load cell transducer (p 0.05).
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Figure 5
W.M. Pereira et al.
RMS value of control limb (mean standard error).
electromyographic characteristics of the vastulateralis in six healthy men with an average age of 30 years and no history of injury to the muscle in question. The authors concluded that an increase in heat led to an increase in the median frequency of the electromyographic signal. The present investigation complements the study cited, as the same relation between the increase in heat and median frequency was found. This phenomenon may be explained by the fact that heat causes vasodilatation, which provides greater blood flow and nutrition to the muscle, allowing it to contract with greater efficiency and increasing the firing rate of the motor units needed for muscle contraction (Thompson, 1985). According to Masuda (1999), median frequency is the parameter least sensitive to noise and most sensitive to physiological and biochemical processes related to sustained contractions and is commonly used in studies on muscle fatigue. The same author also identifies this physiological muscle process based on the sudden drop in the frequency of the electromyographic signal. Gonc ¸alves and Barbosa (2005) analyzed different degrees of exertion on isometric exercises among nine male volunteers. The authors describe a reduction in median frequency and found that an increase in temperature led to a significant increase in the median frequency. In the present study, the biceps brachii muscle submitted to microwave diathermy achieved an increase in median frequency when compared to the control limb, which may be explained by the increase in muscle temperature.
Figure 6 RMS value of heat-treated limb (mean standard error); *significant difference in RMS value (p 0.05).
Figure 7
MF value of control limb (mean standard error).
Farina et al. (2005) analyzed the effect of muscle heating on electromyographic findings and report a directly proportional relationship between the increase in the velocity of muscle nerve conduction and increase in temperature. This process occurs due to electrophysiological alterations, especially an increase in the excitation threshold of the fibers and changes in membrane potential level and permeability, as heat causes an increase in nerve cell metabolism, which leads to a change in cell potential, thereby increasing the velocity of the nerve conduction (Thompson, 1985). Analyzing different muscle groups, Oliveira and Gonc ¸alves (2007) found that amplitude parameters (RMS) were more sensitive than median frequency to alterations caused by fatigue, regardless of the load employed. Regarding the intensity of the electromyographic signal, as demonstrated by the RMS, the present study found that heat caused a significant reduction in electrical activity of the biceps brachii muscle during contraction. Oksa et al. (2002) analyzed the influence of temperature on the electrical activity of the flexor muscles of the arm and found a more intensive increase in electromyographic activation
Figure 8 FM value of heat-treated limb (mean standard error); *significant difference in RMS value (p 0.05).
Influence of heat on fatigue and electromyographic activity of the biceps brachii muscle following the application of ice at a neutral or room temperature. These data demonstrate that an increase in temperature helps to reduce the intensity of the electrical signal and a reduction in temperature leads to an increase in the intensity of the electrical signal during maximal isometric contraction. However, analyzing electromyographic characteristics, Coulange et al. (2006) found no alteration in muscle performance in relation to temperature. As mentioned above, there was a significant difference in the amplitude of the electromyographic signal between the control limb and heat-treated limb, indicating that microwave diathermy led to an important reduction in the intensity of the electromyographic signal. Cardozo and Gonc ¸alves (2003) report that the RMS related to the time domain increased as a result of exercise due to the recruitment and synchronization of motor units in an effort to maintain the level of strength necessary for the exercise and compensate for fatigued motor units. The data from the present study do not corroborate this finding, as there was no significant increase in RMS following the heat treatment, but rather a reduction in the intensity of the electrical signal. During the isometric exercise until the onset of fatigue, there is a time-dependent increase in the electromyographic signal, which confers reliability to the exertion protocol used in the present study (Kumar, 2006; Masuda, 1999; Moritani and Yoshitake, 1998). This increase may occur due to the increase in the amplitude of the action potential, changes in the recruitment order of motor units after the initial seconds of contraction, an increase in motor unit recruitment or an increase in the firing rate of motor neurons. These factors are used as a compensation strategy for the loss of motor function and a sign of muscle fatigue (Sbriccoli et al., 2003; Gonc ¸alves, 2006; Carabajal et al., 2007). In the present study, only the RMS of the biceps brachii muscle was analyzed, whereas muscle strength was assessed using the force read by the load cell, which measured the strength of the elbow flexor muscles, revealing that microwave diathermy led to a significant reduction in the strength of this muscle group. Hunter et al. (2003) analyzed the activation of the elbow flexor muscles during isometric contraction at 90 and found that the load influences muscle performance, demonstrating that the biceps brachii muscle is important to the isometric flexion motion of the elbow. Analyzing muscle performance in the present study, despite the increase in the median frequency of the biceps brachii muscle and increased blood flow due to the heat treatment, there was a reduction in the flexion strength of the elbow. Analyzing the influence of 25% and 50% of maximal isometric strength, Seghers and Spaepen (2004) found that both protocols led to a reduction in strength in 10 healthy adults. These data are similar to those found in the present study, as the individuals exhibited a reduction in maximal isometric strength following the application of heat. Bandeira and Bigaton (2007) analyzed muscle fatigue in the extensor group of the wrist under conditions of normal blood flow and induced ischemia and found a reduction in strength among individuals submitted to the interruption of nutritional blood flow. Based on the findings of the present study, an interruption in blood flow is not the only reason
483
for a reduction in isometric strength, as muscle temperature also proved to be an important factor. This should be interpreted with caution, as elbow flexion strength does not depend on the biceps brachii alone but a set of other muscles as well, such as the brachioradialis, round pronator and flexors of the wrist (Always et al., 1992; Gonc ¸alves et al., 2002). Thus, it cannot be affirmed that the microwave diathermy administered in the present study reached the deep muscles. It must be emphasized that the physiological effects (vascular, metabolic and tissue) obtained by the application of deep heat, are not restricted only to microwaves but to other modalities of diathermy, such as short waves. Therefore, we believe that the results obtained regarding fatigue and muscle strength may be identified with other therapeutic diathermy modalities. However, further studies are needed to investigate the reproducibility of the effects using other modalities. Moreover, the anatomy (size and depth) of the particular muscle group should be taken into consideration in the selection of the diathermy modality and parameters used. We believe that the application time should be prolonged with larger and deeper muscle groups. What we do not know is whether the effects described in this study are reproduced with a greater application time, as the peak temperature increases through diathermy occurs approximately 20 min into the application. Another aspect that must be investigated is the length of time the effects persist. Studies are needed to determine whether the effects persist after a series of exercises. Saga et al. (2008) identified a muscle protector effect after a single exercise session, but the same was not reproduced after a second session.
Conclusion Based on the findings of the present study, heat administered through microwave diathermy had an inhibitory effect on muscle fatigue, as determined for the biceps brachii muscle by the median frequency and electromyographic activity (RMS) values, the latter of which underwent a significant reduction. However, microwave diathermy on the biceps brachii led to a significant reduction in the strength of the elbow flexor muscle group, thereby suggesting that heat should not be used prior to any muscle activity that requires a strength yield. Therefore, the indication for use of this resource must take into consideration the expected results from subsequent therapeutic exercises. Although the results obtained in this study are specific to a single diathermy modality and one muscle group, we believe they can be reproduced with other modalities, such as shortwave, and in other muscle groups. Hence, the present study offers a basis for further studies to reinforce the importance of the use of diathermy as a resource for inhibiting fatigue during physical exercise.
Acknowledgements To Conselho Nacional de Desenvolvimento Cientı´fico e Tecno ´lo ´gico (CNPq).
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Journal of Bodywork & Movement Therapies (2011) 15, 485e495
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EXPERIMENTAL ELECTROMYOGRAPHY STUDY
The influence of kinesiophobia on trunk muscle voluntary responses with pre-programmed reactions during perturbation in patients with chronic low back pain M. Ramprasad, MSPT a,b,*, D. Shweta Shenoy, MSPT, PhD b, Jaspal Singh Sandhu, MS, DSM b, N. Sankara, M.D c a Srinivas College of Physiotherapy and Research Center (SCPTRC), Rajiv Gandhi University of Health Sciences, Mangalore, Karnataka, India b Department of Sports Medicine and Physiotherapy, Guru Nanak Dev University, Amritsar, Punjab, India c Kasturba Medical College (KMC), Mangalore, Karnataka, India
Received 20 June 2010; received in revised form 29 November 2010; accepted 1 December 2010
KEYWORDS Fear of movement; Electromyography; Forceplate; M1-M2 responses; Back pain
Summary The purpose of this study was to examine the relation between fear of movement and perturbation induced electromyographic global trunk muscle voluntary responses with preprogrammed reactions among persons with chronic low back pain (CLBP). CLBP subjects (n Z 25) were challenged to unexpected and expected perturbations on stable and unstable surfaces. ‘Tampa scale for kinesiophobia e Adjusted version-13’ was used to measure kinesiophobia. Regression analysis revealed significant negative correlation between kinesiophobia scores and voluntary responses of rectus abdominis (RA) for unexpected perturbations on stable (r Z 0.69, 95% of CI: 0.85 to 0.40, p < 0.000, r2 Z 0.41) and unstable surfaces (r Z 0.47, 95% of CI: 0.72 to 0.09, p < 0.018, r2 Z 0.29). The activity of erector spinae was not influenced by most of testing conditions in the study except task on unstable surface for expected perturbation (r Z 0.593, 95% of CI: 0.8 to 0.25, p Z 0.002, r2 Z 0.15). RA activity and kinesiophobia score of the CLBP population was significantly inversely associated during anteriorly directed unexpected perturbations. In our study, the significant association between fear of movement and the trunk muscle responses was differentially influenced by expected and unexpected postural demands. ª 2010 Elsevier Ltd. All rights reserved.
* Corresponding author. Department of Sports Medicine and Physiotherapy, Guru Nanak Dev University, Amritsar, Punjab, India. Tel.: þ91 824 2429139, þ91 9343232554; fax: þ91 824 2426766. E-mail address:
[email protected] (M. Ramprasad). 1360-8592/$ - see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.12.002
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Introduction Low back pain is usually a self-limiting musculoskeletal problem, resolving spontaneously although some individuals progress to chronic low back pain (CLBP) and risk factors associated with this transition have been poorly studied from a biomechanical perspective. A plausible contributing factor to chronic low back pain is poor neuro-motor control of trunk muscles in response to postural exigencies of day-to-day activities. Abnormal longer spinal reflex latencies (feedbackward responses) (Reeves et al., 2009), delayed or absence of feed-forwarded CNS mediated pre-programmed reactions (Tsao and Hodges, 2007, 2008), changes in anticipatory postural adjustments (Jacobs et al., 2009) and inefficient/abnormal trunk muscle responses (Hodges and Richardson, 1996; O Sullivan et al., 1998; MacDonald et al., 2010) were consistently reported in CLBP patients during experimentally stimulated postural tasks. These dysfunctions are believed to be important postural control related biomechanical risk factors for occurrence or recurrence of back pain episodes. More studies have stressed the multidimensional causes and identified over one hundred risk factors e.g., Physical: sedentary lifestyle (Odd Ratio 1.31: 95% CI 1.08e1.58), physically strenuous activities (Odd Ratio 1.22: 95% CI 1.00e1.49) (Heneweer et al., 2009), work and work related psychosocial factors (Macfarlane et al., 2009; Nelson and Hughes, 2009) spinal mechanical load (Bakker et al., 2009) lifting heavy weights (Harkness et al., 2003), extended spinal postures (Mitchell et al., 2009), lifting and bending (Hoogendoorn et al., 2000); Psychological: distress, abnormal back pain beliefs, coping strategies, pain self-efficacy, fear of injury/movement, depression, anxiety, hyper-vigilance, stress, maladaptive cognitions and catastrophizing (Mitchell et al., 2010; Smeets et al., 2009; Feuerstein and Beattie, 1995; Schultz et al., 2002) are all risk factors for developing back pain and also transformation of a current episode of back pain into recurrent chronic back pain (Linton, 2000; Marras, 2000; Marras et al., 1995; Norman et al., 1998; Slater et al., 2009; Hides et al., 1996). This transition was extensively influenced by those psychological risk factors which possess moderate (Pincus et al., 2002) to greater risk (Casey et al., 2008; Hasenbring et al., 2001) for developing chronic back pain. Previous studies have demonstrated that psychological variables such as mental and psychosocial stress in CLBP patients resulted in: [1] Less controlled movements, increased trunk muscle coactivation and significantly increased spinal loading (Davis et al., 2002) and [2] Increased spine compression, lateral shear and differences in trunk muscle co-activation (Marras et al., 2000) during lifting maneuvers. Recently, we examined the role of pre-programmed reactions (PPRs) of global trunk muscles as they relate to the balance response, particularly their role in presetting voluntary responses for regaining postural stability after perturbation (Ramprasad et al., 2010). PPRs are continuously cortically modulated for task demands (Lewis et al.,
M. Ramprasad et al. 2004; Pruszynski et al., 2008; Shemmell et al., 2009) and appear at a latency of higher than 40 ms, but before voluntary muscles respond (w120 ms) to postural perturbation (Latash, 2008). As such, we found that PPR responses were absent (<60% of mean reflex) in patients with CLBP who also demonstrated difficulties in modulating PPR during progressively increasing perturbation trial demands. Further we observed CLBP patients with high and low kinesiophobia scores respond differently to postural perturbations. Fear of movement/re-injury, pain related fear, consequent long standing inactivity and fear avoidance are important components of the bio-behavioral model and are believed to be potent risk factors and predictors of chronicity of back pain (Vlaeyen and Linton, 2000; SwinkelsMeewissw et al., 2006; Leeuw et al., 2007; Crombez et al., 1999b). Fear of movement or activity is significantly associated with changes in perception of pain and disability (Meyer et al., 2009; Grotle et al., 2004; Asenlof and Soderlund, 2010), behavioral responses, physical activity, functional capacity (Vlaeyen et al., 1995; Elfving et al., 2007; Geisser et al., 1999), maladaptive cognitions (Reesor and Craig, 1988) abnormal muscle guarding and absence of flexion relaxation ratio (Vlaeyen and Linton, 2000) in the CLBP population. Some investigators have also shown that fear of movement beliefs may predict return to activity in low back pain (Fritz and George, 2002). Studies have cautioned that significant alteration in trunk muscle responses during isometric trunk exertions and forward flexion maneuvers in a sub-group of CLBP patients may be due to fear of executing movement or muscle guarding (Thomas et al., 2008; Geisser et al., 2004; Watson et al., 1997). There is ample evidence that fear of movement influences motor cortex activity and thus motor behavior (Vlaeyen et al., 1995; Vlaeyen and Crombez, 1999; Crombez et al., 1999b; Moseley et al., 2008). Hence it is assumed that the absence of cortically modulated postural control parameters such as anticipatory postural adjustments and pre-programmed reaction in CLBP patients places them at a distinct disadvantage to modulate voluntary responses for a given postural task and this may be further precipitated by fear of movements. Fear of pain and fear of movement are two of the strong possible candidates that influence the amplitude of muscle response and consequently movements of the spine. Whether the magnitude of the fear of pain in people with CLBP reflects the extent of trunk voluntary muscle response dysfunction during postural demands is not clear. The intention of this study was to examine the influence of fear of movement i.e., kinesiophobia on trunk muscle responses elicited through sudden postural challenges in CLBP patients, mimicking the way they respond to unexpected postural demands in day-to-day life. Hence the main aim of the present study was to examine the relationship between trunk muscle voluntary responses measured along with pre-programmed reactions and fear of movement scores obtained from the Tampa scale of kinesiophobia (TSK-Adjusted Version-13) in CLBP patients To date, no studies have reported the association between the magnitude of fear of movement and their influence on trunk muscular responses in CLBP patients
Kinesiophobia measurement during simulated, suddenly perturbed postural challenges i.e., a biomechanical perspective. This study may provide information on how kinesiophobia scores influence cortical modulation characteristics such as PPRs and voluntary responses elicited during perturbation. Further, in this study, stable and unstable platforms were used to find out the influence of kinesiophobia on various surface-induced muscular responses. Anticipatory and non-anticipatory perturbations were added to establish the extent of influence of kinesiophobia scores on trunk muscle responses for expected and unexpected postural threats encountered in activities of daily life. It was hypothesized that the CLBP individuals with low fear scores were more likely to produce higher voluntary peak global trunk muscle responses. This may be vice versa in high kinesiophobia CLBP patients.
Methods Twenty-five (18M 7F) patients with CLBP were selected prospectively, conveniently from the physiotherapy outpatient departments of hospitals affiliated to SCPTRC in Mangalore, a port city in the west coast region of Karnataka, India. Subjects were recruited to participate in a larger study exploring pre-programmed reaction (PPR) dysfunction and specific novel postural control exercises targeting PPRs and their modulation on voluntary responses. The ethical committee of the Department of Sports Medicine and Physiotherapy, of the Guru Nanak Dev University approved the study procedures. Patients with CLBP or non-specific mechanical recurrent low back pain having a pain history of three months and without radiating pain below the buttocks were included in the study. A medical screening was performed by a GP that excluded individuals with CNS impairment, fractures, spondylolisthesis, prolapsed vertebral disc, history of any lumbar, abdominal or limb surgery, spinal tumors, infections, systemic illness and pregnant women. Participants had a mean(SD) age of 40.68 (10.60), mean height of 173.56 (9.269), mean weight of 73.12 (8.30), visual analog scale (VAS, 10 cm) back pain mean of 3.9 (2.4) before testing and Roland Morris disability scale mean of 6.2 (3.6). They had lifetime highest VAS back pain score of 6.4 1.6, 5e23 days of range of annual back pain duration. During the previous 12 months, 63% and 12% of CLBP patients were prescribed pain medications and reported activity reduction respectively during active back pain episodes. All participants provided written, informed consent prior to participation and testing methods of perturbation and reporting procedures were explained. To measure fear of movement, the Tampa scale of kinesiophobia e adjusted version-13 (TSK-AV13) was used, as this scale demonstrated fair internal consistency (a Z 0.68 and 0.80), (Kori et al., 1990; Vlaeyen et al., 1995; Clark et al., 1999) and good validity among CLBP patients (Crombez et al., 1999a, 1999b). TSK-AV is structured on a four-point scale with ranges starting from ‘strongly disagree’ to ‘strongly agree’. Higher scores indicate greater pain related fear of movement (Vlaeyen et al., 1995). Before the perturbation task testing, the TSK-AV was measured and total score was used in the present study.
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Equipment Neurocare e 2000 Surface Electromyography by Bio-tech, India and Bertec forceplate (Columbus, U.S.A) were used to collect data.
Electromyography (EMG) recordings The perturbation technique was adopted from Ramprasad et al’s (2010) research focusing on PPR dysfunction in CLBP patients. AgeAgCl surface, non-disposable electrodes (area: 4 mm) were used and the inter electrode distance was kept at 2 cm. The area for the placement of the electrodes was well rubbed and cleaned with surgical sprit using a swab and for Rectus Abdominis (RA), a pair of recording electrodes were placed on the right and left side of the umbilicus and oriented parallel with the muscle fibers (30 mm lateral to the midline at the level of umbilicus). For lumbar Erector Spinae (ES), a pair of recording electrodes were kept 3 cm lateral to the midline on the right side and left side between L3-L4. The reference electrode was kept approximately 5 cm laterally, to the left side of the lumbar spine. Each bipolar electrode pair was connected to a differential amplifier having input impedance of 108 U, a gain of 1650 and a common mode rejection ratio of 70 dB and A/D converted at a sample rate of 1000 Hz. The EMG machine was set with the following parameters suitable for reflex, PPR and voluntary response measurements i.e., sensitivity: 100mv/div, Filter setting: 20 Hze3 kHz and Sweep speed: 50 ms/div. The extreme low pass filtering with 2.5 or 3 Hz was avoided as it caused distortion of EMG content. Perturbations were given by the release of 3 kg (kgs) cushioned steel cylinders onto the outstretched hand, anteriorly from a height of approximately 8 cms to initiate sudden forward flexion movement on the spine while the subjects were standing on the forceplate. Perturbations were provided unexpectedly and expectedly while standing on a stable platform i.e., forceplate surface and unstable surface i.e., foam surface on forceplate (density 4 16). All the participants were instructed to straighten the arms to a maximum extent to catch the released weight. The time of release was manipulated to set the perturbation anticipatory or otherwise. During expected perturbations, prior instruction for time of weight release, i.e., the precise time, exact second of weight release was communicated to participants and in case of unexpected perturbations the time of weight release was randomly chosen and given without prior knowledge to the participants. A number of trials were made to standardize the weight to bring adequate perturbation to the trunk by releasing weights on the outstretched hand. Weights more than 3 kg tended to produce higher voluntary displacements, i.e., higher EMG voluntary responses in trials; hence it was decided to use 3 kg as the reference weight. However, the weights were adjusted lower or higher to achieve clear reflex as well as PPR responses based on the participant’s body weight (Range 3.5%e5%). Granata et al. (2004) observed sensitive reflex responses for smaller movement disturbance than larger disturbances. Further, the pelvic segment was
488 immobilized by solid support posteriorly and strapped anteriorly to restrain any pelvic movements, and stepping forward from the forceplate. Participants were instructed not to resist before the impact or to let go along with the perturbation, after the impact. However, to gain maximum reflex and PPR amplitude, participants were instructed to return to their previous position as quickly as possible (Bonnet, 1983). Two operators were used to collect the data and were blinded to the kinesiophobia scores of CLBP patients. CLBP patients with high and low kinesiophobia scores were randomly allotted to the experimental tasks. Patients were also blinded to the assumption of the outcome of the study till data analysis, as this could influence performance during the perturbation trials. The first operator was asked to monitor the 5 s of EMG data in real time, using the beep sound of a metronome for every second, and to store the data. The second operator was asked to release the weights coordinately for the beeps, using a randomly assigned second for weight release for each trial subject. Using the known second of COP shift on the forceplate, data was collected and stored 250 ms prior to weight release (baseline data) and after the weight release. The following methods were used to differentiate the PPR amplitudes and voluntary contraction. The guidelines were adapted from previous studies (Hodges and Bui, 1996; Noth et al., 1991).
1) Pre-weight release base line EMG reading was calculated. 2) Minimum two standard deviations from the “pre-weight release base line EMG” after perturbation was accepted for reflex amplitude i.e., M1, present within 40 ms after perturbation. 3) The perturbation was identified by defined millisecond of COP shift from y-axis of COP displacement by considering AP direction of perturbation on forceplate (Minimal 2SD from baseline on forceplate data for minimal 50 ms). 4) For PPR amplitude, the EMG signal present within 120 ms corresponding to forceplate COP shift (center of pressure shift time on forceplate) was considered for data collection. 5) Along with the above method, a visual observation method was also used to identify the onset of welldefined PPR amplitudes i.e., M2-M3 polyphasic waves and voluntary responses. 6) To identify the onset of PPR, the size of the M2 response should exceed the size of the M1 response by atleast 60% (Noth et al., 1991) 7) In cases of generalized delayed responses, particularly in CLBP population, the initial voluntary responses were identified after perturbation and a window length of 80 ms was analyzed from 40 ms to 120 ms for PPR amplitude. PPR was also identified and measured between 40 ms to the voluntary response peak of window length. 8) Peak values of voluntary responses from M2 (rise time) were calculated as RMS PPR combined voluntary response amplitude value (VRPPR).
M. Ramprasad et al. The cursors were introduced at the beginning of M2 to the peak of voluntary response (peak rise time indicated by EMG during 40 mse250 ms) and was traced as the mean PPR combined voluntary response amplitude and considered as RMS amplitude of pre-programmed reactions, along with peak of voluntary response (VRPPR). The window length was also noted. Mean RMS amplitude of PPR to the voluntary response peak amplitude (VRPPR) was calculated for each muscle pertaining to anticipatory/non-anticipatory weight release and stable/unstable surface. A minimum baseline value of 2 m was subtracted from the VRPPR amplitude measurement for three trials of each perturbation and averaged as mean VRPPR RMS amplitude for all participants. Up to six trials for each task were repeated and 30 min rest was given to get well-defined data of M1, M2-M3 and voluntary responses for clear differentiation. The mean VRPPR RMS from three trials was calculated for ES and RA muscles for expected and unexpected perturbations on stable and unstable surface. The mean RMS EMG (200) recordings of either left or right muscles (400) were randomly chosen from the CLBP population to avoid potential bias of taking one side of EMG recording.
Statistical analysis Statistical analysis was performed using SPSS 12.0 Version (SPSS, Chicago, IL) with the significance level set at 0.05. We used ShapiroeWilk’s W test to test the hypothesis that the measurements of each variable came from a population with normally distributed values. If the W test statistic was significant (P Z 0.05), the alternate hypothesis that the measurements came from a non-normally distributed population was accepted, and the variable was subsequently examined using non-parametric statistical tests. The parametric statistical tests were applied when normality assumptions of the variables were satisfied, i.e., non-significant W test value for normal distribution.
Results Test of normality revealed non-normal distribution in the task scores of unstable expected perturbation of RA muscle (ShapiroeWilk: SeW W Z 0.916, p Z 0.041) and stable expected perturbation of ES muscle (W Z 0.914, p Z 0.037). The probability plots for distributions other than the normal were also found for the scores of kinesiophobia (W Z 0.913, p Z 0.036) and disability of CLBP patients (W Z 0.890, p Z 0.011). Hence Spearman’s rho correlation coefficient (r) was computed to quantify association between the mean VRPPR RMS values of various tasks and the scores kinesiophobia. Linear regression was performed to study the extent of influence in RA and ES muscle responses (b1 Z slope or regression coefficient to measure the amount of change in muscle response [y] on kinesiophobia scores [x], r2 Z coefficient of determination for proportion of explained variance between variable) on the predictor variables: stable and unstable surfaces, expected and unexpected perturbations by kinesiophobia scores.
Kinesiophobia measurement
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We found no significant correlation between the ES muscle response on most of the tested tasks in the CLBP population (Fig. 2aec). However a very small effect on ES activity was observed during unstable and expected tasks on kinesiophobia (r Z 0.593, p Z 0.002, r2 Z 0.15) (Fig. 2d). Interestingly patterns of significant negative correlation were found between kinesiophobia scores and voluntary responses of rectus abdominis for unexpected perturbations for stable (r Z 0.691, 95% of CI: 0.85 to 0.40, p Z 0.000), and unstable surfaces (r Z 0.470, 95% of CI: 0.72 to 0.09, p Z 0.018). In all testing conditions expected perturbation tasks of RA did not produce significantly different muscle responses and no significant correlation was found between amplitude of muscle activity and kinesiophobia scores. Our results revealed that patients with lower fear for movement produced larger mean VRPPR RMS amplitudes in RA (F(1, 23) Z 16.60, p Z 0.001, R square Z 0.41, b1 Z 0.491(stable)); (F(1, 23) Z 9.426, p Z 0.005, R square Z 0.291, b1 Z 0.435 (unstable)), (Fig. 1a and c) for unexpected perturbations. The negative slope of the regression line RA scores (Fig. 1aed) indicates that muscle activation decreases as kinesiophobia scores increases and vice versa. Further, CLBP patients with higher fear for movement were found to 40
b Mean RMS values of RA on ST EX task
Mean RMS values of RA on ST UX TASK
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produce lower mean VRPPR RMS on sudden unexpected perturbations in RA muscle. For the above unexpected perturbation tasks, the r2 is 0.41(stable surface) and 0.29 (unstable surface); this result means that 41% and 29% of the variation in the RA muscle responses to these tasks, may be accounted for by knowing the values of the kinesiophobia scores. Despite trunk muscular response differences, this study also found an inverse relation and 90% influence of kinesiophobia scores on disability scores of CLBP patients (r Z 0.98, p Z 0.000, r2 Z 0.9) substantiating similar reports from previous studies (Picavet et al., 2002; Fritz et al., 2001). As we detected significant association between disability and kinesiophobia, an attempt was made to find clear differences between low and high kinesiophobia CLBP group. Median split was method used to separate the low and high kinesiophobia group. ShapiroeWilk goodness of fit statistic revealed that the TSK-AV13 kinesiophobia scores were normally distributed for low kinesiophobia group (SeW W Z 0.905, p Z 0.15) and not for high kinesiophobia group(SeW W Z 0.842, p Z 0.03). The median score was 29 and used as cut off score between high and low kinesiophobia groups. (High kinesiophobia group: > 29, n Z 12, Low kinesiophobia group: 29 n Z 13). ManneWhitney U test revealed significant difference (Z Z 4.257, P < 0.000) between high kinesiophobia and low kinesiophobia CLBP group (Fig. 3).
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Figure 2 Scatterplots and confidence bands for regression line of mean RMS EMG scores of erector spinae muscle in expected (EX(b and d)), unexpected perturbations (UX (a and c)) tasks on stable (ST) and unstable surfaces(US) for kinesiophobia scores of CLBP population.
Test of normality was performed to RA and ES muscles responses of low kinesiophobia group and high kinesiophobia group pertaining to predictor variables tested in this study i.e., stable, unstable surfaces, expected perturbation and unexpected perturbation (2 muscles 2 CLBP groups 2 surfaces 2 types of perturbations Z 16 conditions). ShapiroeWilk test of normality revealed normal distribution of muscle response scores in 15 tested conditions except ES activation on unstable surface, expected perturbation of low kinesiophobia CLBP group (SeW W Z 0.817, p Z 0. 0.011). Hence student t test was performed to find out the difference in trunk muscle responses of normally distributed scores of 15 tested conditions excluding ES muscle response on unstable surface, expected perturbation of low kinesiophobia CLBP group, where ManneWhitney U was performed. To convey the estimated magnitude of relationship between low and high kinesiophobia scores and muscle activity raw mean difference was analyzed. Significantly different peak voluntary responses with preprogrammed reactions were observed between both groups in unexpected perturbations on stable surface [Mean difference (Standard error difference): MD(SED) Z 8.88(1.79), p < 0.001, 95% of CI: 5.16 to 12.6], unstable surface [MD(SED) Z 8.13(2.15), p < 0.001, 95% of CI:
3.67 to 12.6] of rectus abdominus, on stable surface of erector spinae [MD(SED) Z 9.81(4.17), p < 0.028, 95% of CI: 1.17 to 18.45] and not in unstable surface (p < 0.185). ES muscle activity on unstable expected perturbation was found significant between low and high kinesiophobia CLBP group (Z Z 2.339, p Z 0.019). Similar to the regression analysis results, categorical data analysis did not revealed significant pattern of influence between kinesiophobia and ES muscle activity.
Discussion Our study revealed a clear finding that the kinesiophobia scores were inversely associated with the RMS amplitudes of voluntary responses of global abdominal trunk muscles in CLBP population during unexpected anteriorly directed perturbation on stable and unstable surfaces. However erector spinae muscle response to the varieties of perturbation was modestly and differentially influenced by kinesiophobia scores. Our study result were corroborated by the findings of [1] Geisser et al. (2004) who found high pain related fear was significantly associated with reduced lumbar flexion and smaller flexion relaxation ratio
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The box represents the inter-quartile range, which contains the 50% of values. The whiskers are lines that extend from the box to the highest and lowest values, excluding outliers. O = outliers with values. A line across the box indicates the median. N = number of test subjects; L or Low kin.Gr.= Low kinesiophobia group, H or High kin.Gr. = High kinesiophobia group, ST= stable surface, US = unstable surface, UX = unexpected perturbation, EX = expected perturbation, RA = rectus abdominus and ES = erector spinae. Figure 3 Boxplot of kinesiophobia scores and RMS VRPPR EMG values of RA and ES muscle responses of CLBP subjects on varieties of stable, unstable, unexpected and expected perturbation tasks.
[2] Thomas et al. (2008) reported CLBP patients high in pain related fear specifically avoid activation of the abdominal muscles during maximal isometric trunk exertions and [3] Lamoth et al. (2004) reported fear of pain and induced pain had subtle effects on ES EMG activity during walking. The interesting observation in our study was elevated significant and non-significant ES muscle response to most perturbation tasks compared to the pattern of significant lower mean RMS RA muscle responses in all tasks and particularly to unexpected perturbation tasks (Fig. 3). Similar increase in EMG activity of ES muscle during trunk flexion was reported in previous studies (Ershad et al., 2009; Van Diee ¨n et al., 2003) emphasizing the use of greater antagonistic co-contraction for spinal stability to control the trunk flexion in CLBP population (Franklin and Granata, 2007). However ES activity was influenced minimally below 16% (Fig. 2d) and negatively during complex tasks such as unstable and expected perturbation (r Z 0.593, p Z 0.002, r2 Z 0.15). However it must acknowledged that there was a higher mean difference in ES muscle activity compared to RA muscle activity between both the CLBP groups on
stable, unexpected perturbation than unstable expected perturbation (Fig. 3). This finding reveals that ES muscle activity during postural demands was differentially influenced by and surface related factors and governed by various other factors not tested in our study. The outcome was quite similar before (Regression analysis) and after splitting up the data except one additional task was found significant in ES muscle activity i.e., unstable expected perturbation task after curving up. No clear significant relationship of patterns between ES muscle activity and kinesiophobia scores was found on the two different analyses. We found kinesiophobia scores had significant influence on abdominal muscle responses elicited during unexpected perturbation rather than expected perturbation. One explanation might be the anteriorly directed, visually cued load release used in this study for perturbation tasks. Sudden postural adjustments with reduced trunk flexion (Geisser et al., 2004) and associated abdominal muscle responses, produced during anticipated unexpected (unknown time of weight release) upper extremity loading tasks, on stable and unstable surfaces, was negatively influenced by kinesiophobia scores. However the anticipated perturbation, with prior known time of weight release, was not influenced by kinesiophobia scores. One
492 possible explanation is that attention was focused away from the pain during expected perturbation and on pain during unexpected perturbation (Butler et al., 2010). Our findings support the hypothesis proposed by Kronshage et al. (2001) and Leonhardt et al. (2009) that increased scores of fear of movement is associated with specific movement avoidance, perceived as a dangerous component of a task, rather than general task avoidance. Studies have reported similar findings i.e., decreased muscle activation for pain related fear during trunk extensioneflexion task, a weight lifting task and submaximal isometric upper extremity physical task in trunk and upper scapular muscles (Crombez et al., 1999a, 1999b; Nederhand et al., 2006). Caution is warranted while interpreting studies using the methods described above. (Marras and Davis, 2001). This is because EMG protocols with isometric EMG exertions (Sub-maximal voluntary contraction) and flexion relaxation ratio were innately associated with problems in normalization, motivational aspects and movement execution errors respectively. The striking difference in our study was pragmatic perturbation methodology to test the muscle activation and fear of movement simulating daily life’s postural demands i.e., perturbation method not influenced by the above mentioned factors. Some aspects of our methodology warrant discussion related to our results. First, the manual perturbation method adopted in our study and the need for a control group with healthy individuals. Despite the fact that weight release-perturbation method was a manual process, it was found to result in authentic fair voluntary responses from trunk muscles by diverting the participant’s attention to follow the weight release. The intra-class correlation coefficient (ICC (Two way mixed effects)) showed fair reproducibility of RA (ICC Z 0.4, 95% of CI: 0.34 to 0.78) and ES (ICC Z 0.3, 95% of CI: 0.43 to 0.77) EMG muscle responses over different perturbations. Our study results have many research and clinical implications. The main research implication of this study is that trunk muscle evaluation without controlling fear of movement or fear avoidance beliefs in CLBP may lead to abnormal findings and conflicting predictions on responses of trunk muscle during various activities. Therefore, more attention is needed to address fear related factors in methodological (inclusion, exclusion and matching criteria of participants) as well as statistical issues (e.g., covariates, predictors and confounders) while evaluating trunk muscle responses of CLBP population. In the clinical perspective of fear of movement, two important issues need to addressed while rehabilitating high and low fear sub-group of CLBP population 1] missing defense in low fear CLBP sub-group which may lead to higher muscle activation and 2] high fear of movement associated with abnormal lower muscle activation in the agonist muscle of this subgroup of CLBP group. Early rehabilitation should focus on finding the specific movement dysfunction associated with high fear and gradual training may lead to reduction in abnormal trunk muscle response in these patients. Low fear CLBP group can be trained for specific exercises focusing on postural alignment, postural control reactions or mimicking postural control strategies. These specific exercises targeting pre-programmed reactions may contribute to fine tuning of voluntary responses at the cortical level necessary
M. Ramprasad et al. for postural demands and adjustments (Pedersen et al., 2007). On the other hand, studies reported that CLBP patients were found with decreased (5e11%) prefrontal and thalamic gray-matter density and disruptions in functional connectivity of cortical regions despite performing the task equally as well as controls (Marwan et al., 2008; Apkarian et al., 2004). Hence it is important to identify, evaluate and intervene in psychological variables such as fear avoidance beliefs, depressive mood, maladaptive pain related coping strategies, mental stress, tendency to catastrophize and appraisals of control and to identify their influence on CLBP, as this may significantly change muscle response by reducing pain intensity, disability (Waddell et al., 1993; Woby et al., 2004) and further reduce the risk that transient symptoms might develop into chronic illness (Lundberg, 2003, 1999). We propose that along with cortical functional disruptions and CNS related modulation dysfunction in presetting the voluntary response, a phase of high fear of movement with lesser muscular excursions, and a phase of low fear of movement with higher peak muscle responses, may act as a cycle leading to chronic LBP. Further with the absence of cortically modulated fine tuning, sudden trunk movements to postural adjustments may result in abnormal amplitudes of global trunk muscle responses in a sub-group of CLBP patients. These abnormal muscular responses may induce abnormal translation of vertebrae causing impingement in the neutral zone and may result in spinal instability (White and Panjabi, 1990). Klenerman et al. (1995) and Vlaeyen and Linton (2000) proposed that pain related fear was a potent precursor for developing chronic low back pain from an episode of acute low back pain. In addition Klenerman et al. (1995) predicted 66% of acute sufferers went on to become CLBP, using fear-avoidance variable alone in their study. Interestingly prospective cohort studies support this notion. Carragee et al. (2005) with 5 year follow-up study, predicted development of serious LBP in patients with both structural and psychosocial risk factors by examining baseline psychosocial variables. Further a study by Feyer et al. (2000) with 4 year prospective follow-up found psychological distress to be a significant etiologic and prognostic factor for CLBP. Van Nieuwenhuyse et al. (2006) revealed relative risk of 1.8 for the high scores of pain related fear in the development of low back pain. More studies are needed on the bio-behavioral factors (Feuerstein and Beattie, 1995; Iezzi et al., 1992) particularly fear of movement and their influence on functional cortical activation and muscle related modulation dysfunction. This may reveal the relative contribution of these factors in development of CLBP. Further integrated studies focusing on temporal partitioning of EMG activation patterns i.e., short, long latency reflexes and voluntary responses during postural demands and kinesiophobia induced relative modulation on the above temporal entities may provide more insight and hopefully contribute to the prevention of CLBP from an acute episode. Cognitive-behavioral interventions should be coherently and coordinatedly given along with essential physical therapy interventions or vice versa and or personalized to the need of this population. In other words, periodic kinesiophobia evaluation and cognitive-behavioral evaluation
Kinesiophobia measurement with minimal clinically important difference score can be used to progress the graded exercise therapy interventions or with combined therapy approaches (George et al., 2004; Monticone et al., 2008). More randomized control trials in this area may provide deeper understanding of the combination of these therapies in CLBP rehabilitation.
Conclusion Our study confirms that kinesiophobia in CLBP patients differentially influences trunk muscle activation levels during sudden postural demands. The findings of this study provide preliminary data on specific muscle activation dysfunction during perturbation-induced postural demands in CLBP patients, further substantiating the evidence that fear of movement is associated with specific movements rather than whole task.
Clinical implications C
C
Early and periodic screening to identify kinesiophobia, fear of pain and the nature of fear avoidance beliefs in acute, sub-acute and chronic back pain patients can be helpful in detailed physical examination, to choose and change the course of interventions in CLBP population particularly with non-specific LBP pathologies possibly without further referral and diagnostic procedures. Physical therapy interventions optimizing high kinesiophobia induced specific movement dysfunction or low kinesiophobia associated with abnormal global trunk muscle amplitudes can be tailored with cognitivebehavioral evaluation for prescribing and progressing graded exercises for cost-effective management and an early recovery.
Acknowledgements The authors thank A Shama Rao Foundation, Mangalore and Srinivas, Wenlock, ESI and Port-Trust Hospitals, Mangalore and Narayanan, M.S.P.T., Anup Johney, M.S.P.T., for their profound assistance in carrying out the study. Thanks to Selvamani, M.P.T., Balasubramanian, M.P.T., John Varghese, M P T for assisting statistical works, manuscript preparation, revisions and anonymous reviewers for their inputs. There are no conflicts of interest for the authors and the outcome of this study. This project was supported in part with a grant from SCPTRC, Mangalore, Karnataka, India.
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Journal of Bodywork & Movement Therapies (2011) 15, 496e501
available at www.sciencedirect.com
journal homepage: www.elsevier.com/jbmt
SENSORY-MOTOR REHABILITATION
Analysis of electromyographic activity of ankle muscles on stable and unstable surfaces with eyes open and closed* Luiz Alfredo Braun Ferreira, MSc a, Wagner Menna Pereira, MSc a, Luciano Pavan Rossi, MSc b, Ivo Ilvan Kerpers, MSc b, Alderico Rodrigues de Paula Jr, PhD a, Claudia Santos Oliveira, PhD c,* a
Universidade do Vale do Paraı´ba (UNIVAP), Brazil Universidade Estadual do Centro-Oeste (UNICENTRO), Brazil c Universidade Nove de Julho (UNINOVE), Brazil b
Received 22 September 2009; received in revised form 23 August 2010; accepted 3 September 2010
KEYWORDS Electromyography; Ankle; Proprioception
Summary Introduction: Proprioceptive exercises are performed on a daily basis in physiotherapy with the use of different unstable platforms in order to improve joint stability using the mechanical and sensory properties of ligaments, joint capsule and integrated activity of the muscles surrounding the joint. Changes in the myoelectrical characteristics of the muscles during activity can be identified using surface electromyography (EMG), which provides important information on the behavior of muscles submitted to different types of load. Objectives: The aim of the present study was to analyze the electromyographic activity of the tibialis anterior, tibialis posterior, peroneus longus, gastrocnemius lateralis and gastrocnemius medialis on stable and unstable surfaces with eyes open and closed. Methodology: Twenty-five active, healthy, male and female individuals were submitted to an anthropometric evaluation and a protocol involving warm up and the electromyographic assessment of muscle activity on different surfaces. The order of the data collection was chosen randomly by lots [on stable ground or unstable platforms (trampoline, balance platform, proprioceptive disk and proprioceptive board) with eyes open and on a trampoline, balance platform and stable ground with eyes closed]. The individuals remained balanced on these surfaces for 15 s with the knee at 30 flexion in order to provide greater instability. Results: There was a significant increase (p < 0.05) in muscle activity on the unstable surfaces, with the exception of the trampoline, which did not achieve statistically significant differences
*
Study carried out at the Universidade Estadual do Centro-Oeste UNICENTRO. ´gua Branca, Sa * Corresponding author. UNINOVE, Av. Francisco Matarazzo, 612, A ˜o Paulo 05001-100, Brazil. E-mail address:
[email protected] (C.S. Oliveira).
1360-8592/$ - see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.09.003
Analysis of electromyographic activity of ankle muscles on stable and unstable surfaces with eyes open and closed
497
in relation to the stable ground. The tibialis anterior and peroneus longus exhibited the greatest electromyographic activity on all surfaces. The proprioceptive tests performed with eyes closed exhibited significantly greater electromyographic activity than with eyes open. Conclusion: Proprioceptive exercises on unstable surfaces generated a significant increase in electromyographic activity, especially with eyes closed, and are therefore a valuable resource in the sensory-motor rehabilitation of the ankle. ª 2010 Elsevier Ltd. All rights reserved.
Introduction A number of studies have investigated both the extrinsic and intrinsic risk factors of sprained ankles (Mchugh et al., 2006). One of the most challenging aspects for practitioner is understanding the role of mediated proprioceptive neuromuscular control following an injury and restoration through rehabilitation. Proprioception contributes toward the precise delineation of the motor programming necessary to the neuromuscular control of movement and muscle reflexes, thereby providing dynamic joint stability. Ligament trauma and proprioceptive functional deficiency lead to mechanical instability, which could ultimately lead to microtrauma and further injury (Lephart et al., 1997). Balance is defined in two forms e static and dynamic. Static and dynamic balance is maintained by the vestibular (inner ear, cochlear nerves, pathways and interrelation in the central nervous system), visual and proprioceptive systems, with the sensory receptors located in joints, muscles and tendons (Horak and Shupert, 1994; Lee and Aronson, 1974). Disorders in one or more of these systems affect balance. The vestibular system contributes toward maintaining the body in equilibrium as well as coordinating the movements of the head and body. However, vestibular signals alone are not capable of providing information to the central nervous system (Horak and Shupert, 1994). The vestibular system participates in the accurate processing of sensory information regarding postural movements, thereby fulfilling multiple functions in postural control (Buzatti et al., 2007). The visual system assists in the maintenance and orientation of an erect posture. The conscious and unconscious correction of posture is possible through visual inputs. Although the visual system is an important reference source of verticality and for the maintenance of the natural oscillation of the body within the limits of stability, it is not essential to postural control, as it is possible to maintain one’s balance with one’s eyes closed (Horak and Shupert, 1994). The proprioceptive system describes the awareness of posture, movement and changes in balance. This system is a specialized variation of the sense of touch and encompasses sensations of joint movement (kinesthesia) sense of joint position (Willems et al., 2002). When these three systems are in harmony, there is perfect spatial orientation, with eye and spinal reflexes appropriate to the automatic, unconscious maintenance of postural control. Moreover, in structures placed in disequilibrium, as in the case of the ankle, there are both static and dynamic reflexive protection mechanisms. Electromyography (either alone or in combination with other biomechanical methods) offers important information on the behavior of muscles when submitted to different types
of load as well as diverse execution angles and velocities (Silva and Gonc ¸alvez, 2003). This method also assesses myoelectric behavior under different circumstances, such as body and room temperature, neuromuscular training, etc (Weller et al., 1998; Oksa et al., 2002; Racinais et al., 2005; Shin et al., 2006). Functional training on unstable platforms is an important aspect of neuromuscular rehabilitation and conditioning and consequently furnishes improvement in coordination and the neuromuscular recruitment pattern (Stronjnik et al., 2002). During physical training, the instability of movement places joints in situations of risk. Thus, the activation of proprioceptive impulses that are integrated in various sensorymotor centers regulates adjustments in the contraction of postural muscles, thereby maintaining general postural balance (Cooke, 1980). Considering the need for determining protocols for the identification of muscle activity in proprioceptive exercises through surface electromyography, the aim of the present study was to analyze the electromyographic activity of tibialis anterior, tibialis posterior, peroneus longus, gastrocnemius lateralis and gastrocnemius medialis (anklestabilizing muscles) on stable and unstable ground with eyes open and closed.
Materials and methods This study was carried out at the Physiotherapy Clinic of the hospital of the Universidade Estadual do Centro-Oeste (city of Guarapuava, Parana ´, Brazil). Twenty young, healthy adults between 19 and 24 years of age (10 males and 10 females) from a total of 40 subjects participated in the study. Selection of the participants was based on the following inclusion criteria: age between 18 and 28 years; no distinction regarding ethnic background or gender; active individuals that did not participate in proprioceptive training or balance exercises; and a sports background. The exclusion criteria were musculoskeletal pathology, neuro-degenerative or infectious disease, chronic ankle instability, recent ankle sprain, vestibular pathology and visual impairment. All participants were informed as to the procedures of the experiment and signed terms of informed consent in compliance with the Norms for Research on Human Subjects (National Health Council Resolution n 196/96). The study received approval from the Ethics Committee of the Universidade do Vale do Paraı´ba (n H 50/CEP/2008). The tibialis anterior, tibialis posterior, peroneus longus, gastrocnemius lateralis and gastrocnemius medialis were chosen for analysis due to their being considered muscles of key activity during monopodal support (Moore and Dalley, 2001; Smith et al., 1997). The non-use of the soleus muscle in the present study is justified by the fact that it is
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a tonic postural muscle and constantly activated when standing on either one or both feet (Smith et al., 1997). Tests were performed with eyes open and closed on both stable and unstable surfaces. Tables 1e3 display the anthropometric data on the participants. Data collection on unstable (trampoline and balance platform) and stable surfaces with eyes open and closed were carried out randomly by lots regarding the order of the exercises to impede motor learning. Active bipolar electrodes were placed at a distance of 20 mm from center to center (Hermens, 1999). Trichotomy and cleaning of the areas were first performed in order to reduce bioimpedance, based on the recommendations of the Surface Electromyography for the Non-Invasive Assessment of Muscles (Hermens, 1999). The placement of the electrodes followed the anatomical reference method described by Delagi and Perotto (1980). An additional electrode was placed over the bone protuberance to serve as a neutral reference point, thereby diminishing external signals and noises. The reference electrode is necessary in order to have a common reference for the differential amplifier and should be placed, whenever possible, over an electrically neutral tissue (generally a bone protuberance) (De Luca, 1997). The ability of the amplifier to reject signals common to both inputs is called the ratio of common-mode rejection (RRMC). For the best record, filters are available that remove unwanted frequencies using high pass, low pass and band pass (Ocarino et al., 2005; Correa et al., 2003). Each individual warmed up for 5 min on a treadmill, following the guidelines of the American College of Sports Medicine e ACSM (2007), which recommends warm up prior to any physical activity or exercise. The assessment of muscle activity was performed on the dominant leg with the subject barefoot and the other leg lifted off the ground with the knee in semi-flexion. For greater muscle activation, a 30 angle of knee flexion on the support leg was standardized using a goniometer in order to avoid the lock and screw mechanism on the knee, which would lend greater stability to the ankle. Data collection time for electromyographic activity was 15 s on all types of surface, with a 1-min rest period between readings, totaling an average of 10 1 min of collection time. An eight-channel electromyograph (EMG System Brasil Ltda.) with active, bipolar, differentiated surface electrodes was used for the acquisition of the electromyographic signal. The electromyograph was connected to the Windaq signal acquisition software program, with the signal passing through a 20e500 Hz band pass filter, amplified 1000 times and converted by an A/D board with a sampling frequency of 2000 Hz for each channel and an input variation of 5 mV. The data were analyzed using the Matlab 7.0 signal processing program (MatWorks) and Origin 7.0 program
Table 1
Age (years)
Height (cm)
Weight (kg)
BMI
21 1
170 6
64 11
22 3
Mean standard deviation of anthropometric characteristics.
Characteristics of the sample of men.
Mean Standard Error
Age (years)
Height (cm)
Weight (kg)
BMI
21 1
170 6
73 8
24 2
Mean standard deviation of anthropometric characteristics.
(Massachusetts, USA). Descriptive and inferential statistics were performed using the Statistical Package for the Social Sciences 13.0 (SPSS, Illinois, USA). The Sharpiro-Wilk test was used to determine the normality of the data, with a 5% level of significance (p 0.05). As some variables did not exhibit normal distribution, the non-parametric Wilcoxon test was used for the comparison of mean values, with a 5% level of significance (p 0.05).
Results The results are presented as mean and standard error for the inferential statistics in relation to the mean amplitude values of the electromyographic signal (root mean square) of the tibialis anterior, tibialis posterior, peroneus longus, gastrocnemius lateralis and gastrocnemius medialis during the different perturbation exercises (Table 4). Figure 1 shows that the gastrocnemius medialis muscle exhibited no significant difference (p > 0.05) in values between eyes open and closed. Figure 2 displays the muscle activity on the trampoline, revealing considerable activity in the tibialis anterior and peroneus longus with eyes closed. In contrast, median activity occurred in the other muscles. All values were significant (p < 0.05) for the muscles analyzed. Figure 3 displays the electromyographic activity between eyes open and closed on the balance platform, revealing greater activity for all muscles in comparison to the other types of surface, with the greatest activity in the tibialis anterior and peroneus longus. However, the gastrocnemius medialis exhibited no significant difference (p > 0.05) in values between eyes open and closed. Thus, the tibialis anterior and peroneus longus exhibited the greatest activation in comparison to the other muscles, regardless of the type of ground. This demonstrates that both muscles are important dynamic stabilizers of the ankle joint, with the tibialis anterior acting as an invertor and dorsiflexor and the peroneus longus acting as an evertor and plantar flexor. The function of inversion and eversion should be stressed, as most unstable grounds have lateral-medial instability. This may explain why these two muscles were more active during all the perturbation exercises.
Table 3
Characteristics of the sample.
Mean Standard Error
Table 2
Characteristics of the sample of women.
Mean Standard Error
Age (years)
Height (cm)
Weight (kg)
BMI
21 1
170 6
56 7
21 2
Mean standard deviation of anthropometric characteristics.
Analysis of electromyographic activity of ankle muscles on stable and unstable surfaces with eyes open and closed Table 4
499
Significance values (p < 0.05) of all exercises performed compared to the stable ground.
BALANCE TRAMPOLINE BALANCE (EC) TRAMPOLINE (EC) STABLE (EC)
TA
PL
LG
GM
TP
0.000227 0.038432 4.8E-10 3.52E-10 2.83E-07
0.000222 0.092328 6.67E-07 2.85E-07 3.14E-07
2.23E-05 0.162251 3.42E-08 4.43E-06 5.16E-06
0.008667 0.339999 3.43E-07 0.001334 0.010681
3.37E-06 0.318043 9.3E-11 1.58E-05 4.26E-05
Underlined values were not statistically significant (p > 0.05); EC: Eyes Closed; TA: Tibialis anterior; PL:Peroneus longus; LG: Gastrocnemius lateralis; GM: Gastrocnemius medialis; TP:Tibialis posterior.
In the analysis of the total mean values on the different types of ground (Figure 4), the results reveal greater muscle activation with eyes closes in comparison to eyes open, especially on the balance platform. The data obtained using the trampoline merits attention, as similar muscle activity to that on stable ground with eyes open was demonstrated; however, when the visual system was inhibited, the electromyographic activity increased significantly (Figure 4). Figure 5 depicts the comparison of electromyographic activity between men and women, revealing no significant difference in muscle activity between genders, as the data on the gastrocnemius medialis between genders achieved a p-value of 0.0561.
Discussion No studies were found in the literature using the same characteristics and variables analyzed in the present investigation. However, there are studies assessing muscle reaction time, muscle activation on different types of ground and muscle activity following proprioceptive training on unstable ankles (Osborne et al., 2001; Cunha and Bonfim, 2007). There were no significant gender differences in the present study, which demonstrates the homogeneity of the sample. This lack of gender difference may be explained by the fact that the individuals had similar physical characteristics, such as a body mass index within the ideal range
Figure 1 Variation in electromyographic activity (root mean square) between eyes open and eyes closed on stable ground (Mean Standard Error); ) No significant difference in electromyographic activity (p > 0.05)
and a low standard deviation, as well as by the independent comparison of the electromyographic activity in a single individual on the different unstable surfaces. The greatest source of ankle mechanoreceptors is believed to be in the ligaments, which are responsible for the proprioception and maintenance of joint stability. The presence of Ruffini endings, Pacinian corpuscles and Golgi tendon organs in the ligaments of the ankle has been demonstrated histologically (Verhagen et al., 2005). Thus, exercises on unstable ground generate rapid changes in the length of the ankle ligament due to the stimulation of the joint on multiple planes of movement, thereby generating afferent stimuli and reflexive motor responses in order to produce rapid joint stability (Myers et al., 2003). According to Oliveira et al. (2006), the aim of this type of training is to induce unforeseen perturbation, thereby stimulating the stabilization reflex and the production of agonist-antagonist co-contraction. A previous electromyographic study assessed the tibialis anterior and gastrocnemius medialis in five individuals during the use of two balance platform models on different supports. The results revealed greater myoelectrical activity in the gastrocnemius medialis in comparison to the tibialis anterior during tests with the feet both closer together and further apart on both types of proprioceptive boards (Oliveira et al., 2006). In contrast, the tibialis anterior exhibited greater electromyographic activity on both stable and unstable ground in the present study and was the most solicited muscle.
Figure 2 Variation in electromyographic activity (root mean square) between eyes open and eyes closed on trampoline (Mean Standard Error); all values denote significant difference in electromyographic activity (p < 0.05)
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Figure 3 Variation in electromyographic activity (root mean square) between eyes open and eyes closed on balance platform (Mean Standard Error); ) No significant difference in electromyographic activity (p > 0.05)
Other studies stress the importance of the visual system regarding postural control in humans. Lee and Aronson (1974) carried out an experiment in order to understand the effect of the visual system on the control of the body. The authors investigated visual information by moving a suspended “room” in which the roof and lateral walls were able to move. Adults and children remained standing in this room while it was moved and the corresponding body oscillations were observed, demonstrating the considerable influence of the visual system over postural control (Lee and Aronson, 1974). Mochizuki et al. (2007) determined factors that influence the co-modulation rate of the motor unit load in the soleus muscle of both legs in a standing position with eyes open and closed and vibration on the calcaneus tendon. The results revealed that the common program for motor neurons of the two muscles exhibited no difference between standing up with eyes open or closed, but there were significant differences in relation to vibration. These results suggest that proprioception and subcortical inputs contribute toward the co-modulation of the activation rate of the pairs of muscle units in the soleus muscle of the right and left leg during static posture.
Figure 5 Variation in electromyographic activity (root mean square) between men and women on unstable ground (Mean Standard Error); No significant difference in electromyographic activity in all comparisons (p > 0.05); TA: Tibialis anterior; PL:Peroneus longus; LG: Gastrocnemius lateralis; GM: Gastrocnemius medialis; TP:Tibialis posterior
The present study investigated the effect of visual and proprioceptive information on muscle activation in the ankle regarding the maintenance of static balance in healthy young adults. The results reveal that, through sensory deprivation or perturbation, ankle muscles vary in activity, which is in agreement with previous studies. Thus, we can readily see the importance of the visual system in the proprioceptive action of the body, stressing its role in postural control and possible implications for the rehabilitation process.
Conclusion The results of the present study reveal a significant increase in muscle activity on the majority of unstable surfaces in comparison to stable ground, with a significantly greater increase when the eyes are closed, except in the gastrocnemius medialis. The techniques employed therefore proved effective in activating ankle muscles and are of fundamental importance to the sensory-motor rehabilitation of this joint. Further studies are needed for the analysis of the influence of different surfaces, different types of data collection and the removal of the visual system during other types of exercises in order contribute scientific knowledge regarding the influence of proprioceptive training over the performance of the protective musculature of the ankle.
References
Figure 4 Total mean electromyographic activity with eyes open and closed on different surfaces (Mean Standard Error)
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Analysis of electromyographic activity of ankle muscles on stable and unstable surfaces with eyes open and closed Buzatti, D.R.P., et al., 2007. Reabilitac ¸a ˜o Vestibular. Revista Fisioterapia Brasil 8 (1) jan/feb. Cooke, J.D., 1980. The role of stretch reflexes during active movements. Brain Res. 181, 493e497. Correa, P.P., Santos, P.M., Veloso, A., 2003. Electromiografia: fundamentac ¸a ˜o fisiolo ´gica, me ´todos de recolha, processamento e aplicac ¸o ¸o ˜es cinesiolo ´gicas. Edic ˜es FMH, Lisboa. Cunha, P.L., Bonfim, T.R., 2007. Ativac ¸˜ ao eletromiogra ´fica em exercı´cios sobre a prancha de equilı´brio. Revista Fisioterapia Brasil 8, 192e197. De Luca, C.J., 1997. The use of surface electromyography in biomechanics. J. Appl. Biomech. 13 (2), 135e163. Delagi, E.F., Perotto, A., 1980. For the electromyographer: the limbs. Phys. Med. Rehabil.. Hermens, H.J., 1999. European Recommendations for Surface Electromyography e SENIAM 16e17. Horak, F.B., Shupert, C., 1994. The role of the vestibular system in postural control. In: Vestibular Rehabilitation. FA Davis, New York, pp. 22e46. Lee, D.N., Aronson, E., 1974. Visual proprioceptive control of standing in human infants. Percept Psychophys 15 (3), 529e532. Lephart, S.M., Pincivero, D.M., Giraido, J.L., Fu, F.H., 1997. The role of proprioception in the management and rehabilitation of athletic injuries. Am. J. Sports Med. 25, 130. Mchugh, M.P., Tyler, T.F., Tetro, D.T., Mullaney, M.J., Nicholas, S.J., 2006. Risk factors for Noncontact ankle sprains in high School Athletes: the role of Hip strength and balance ability. Am. J. Sports Med 34, 464. Mochizuki, G., Ivanova, T.D., Garland, S.J., 2007. Factors affecting the Common modulation of bilateral motor unit discharge in human soleus muscles. J. Neurophysiol. 97, 3917e3925. Moore, K., Dalley, A., 2001. Anatomia orientada para clinica, 4 ed Rio de Janeiro: Guanabara Koogan. Myers, J.B., Riemann, B., Hwang, J., et al., 2003. Effect of peripheral afferent alteration of the lateral ankle ligaments on dynamic stability. Am. J. Sports Med. 31 (4), 498e506. Ocarino, J.M., Silva, P.L.P., Vaz, D.V., Aquino, C.F., Brı´cio, R.S., Fonseca, S.T., 2005. Eletromiografia: interpretac ¸˜ ao e
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aplicac ¸o ¸a ˜es nas cie ˆncias da reabilitac ˜o. Revista Fisioterapia Brasil 6 (4), 305e309. Oksa, J., Ducharme, M.B., Rintama ¨ki, H., 2002. Combined effect of repetitive work and cold on muscle function and fatigue. J. Appl. Physiol. 92, 354e361. Oliveira, F.B., et al., 2006. Avaliac ¸a ˜o de dois modelos de ta ´bua proprioceptiva com dois tipos de apoios por meio da eletromiografia de superfı´cie. Fisioterapia Brasil 7 (3) Maio/Junho. Osborne, M.D., Chou, L.S., Laskowski, E.R., Smith, J., Kaufman, K.R., 2001. The effect of ankle disk training on muscle reaction in subjects with a history of ankle sprain. Am. J. Sports Med. 29 (5), 627e632. Racinais, S., Blonc, S., Jonville, S., Hue, O., 2005. Time of day influences the environmental effects on muscle force and contractility. Med. Sci. Sports Exerc. 37 (2), 256e261. Shin, H.K., Cho, S.H., Lee, Y.H., Kwon, O.Y., 2006. Quantitative EMG changes during 12 week DeLorme’s axiom strength training. Yonsei Med. J. 47 (1), 93e104. Silva, S.R., Gonc ¸alvez, M., 2003. Comparac ¸a ˜o de Protocolos para Verificac ¸a ˜o da Fadiga Muscular pela Eletromiografia de Superfı´cie. Motriz, Rio Claro 3 9 (1), 51e58. Smith, L., Weiss, E., Lehmkuhl, D., 1997. Cinesiologia Clı´nica de Brunnstrom, 5a ed. Editora Manole, Sa ˜o Paulo. Stronjnik, V., Vengust, R., Pavlovic, V., 2002. The effect of proprioceptive training on neuromuscular function in patients with patellar pain. Cell Mol. Biol. Lett. 7 (1), 170e171. Verhagen, E., Van Der Beek, A., Twisk, A., Bouter, L., Bahr, R., Van Mechelen, W., 2005. An economic evaluation of a proprioceptive balance board training programme for the prevention of ankle sprains in volleyball. Br. J. Sports Med. 39, 111e115. Weller, A.S., Greenhaff, P.L., Macdonald, I.A., 1998. Physiological responses to moderate cold stress in man and the influence of prior prolonged exhaustive exercise. Exp. Physiol. 83, 679e695. Willems, T., Witvrouw, E., Verstuyft, J., et al., 2002. Proprioception and muscle strength in subjects with a history of ankle sprain and chronic instability. J. Athl Train. 37 (4), 487e493.
Journal of Bodywork & Movement Therapies (2011) 15, 502e506
available at www.sciencedirect.com
journal homepage: www.elsevier.com/jbmt
PILOT STUDY
Reliability testing of the patellofemoral joint reaction force (PFJRF) measurement in taped and untaped patellofemoral conditions during single leg squatting: A pilot study Javid Mostamand, MSc PT, PhD a,*, Dan L. Bader, DSc b, ¨ Hudson, PhD, MCSP c Zoe a
Musculoskeletal Research Centre, Isfahan University of Medical Sciences, PO Box 164, Isfahan 8174673461, Iran Department of Engineering, Queen Mary University of London, Mile End Road, London E1 4NS, UK c Centre for Sports and Exercise Medicine, Barts and the London Queen Mary’s School of Medicine and Dentistry, Mann Ward, Mile End Hospital, Bancroft Road, London E1 4DG, UK b
Received 3 October 2010; received in revised form 23 November 2010; accepted 2 December 2010
KEYWORDS Patellofemoral pain syndrome; PFJRF reliability test; Patellar taping
Summary Introduction: Measuring patellofemoral joint reaction forces (PFJRF) may provide reliable evidence for patellar taping to correct probable malalignment in subjects with anterior knee pain, or patellofemoral pain syndrome (PFPS). The aim of the present study was to examine the reliability of PFJRF measurements in different patellofemoral conditions during squatting in healthy subjects. Methods: Using a motion analysis system and one forceplate, PFJRF of eight healthy subjects was assessed during single leg squatting. Data was collected from superficial markers taped to selected landmarks. This procedure was performed on the right knees, before (BT), during (WT) and shortly after patellar taping (SAT). The PFJRF was calculated using a biomechanical model of the patellofemoral joint. Results: The results revealed that, there were no significant differences between the PFJRF mean values for three conditions of BT (2100.55 455.25), WT (2026.20 516.45) and SAT (2055.35 669.30) (p > 0.05). The CV (coefficient of variation), ICC (intra class correlation coefficient), LSD (least significant difference) and SEM (standard error of measurement) values revealed the high reliability of PFJRF measurements during single leg squatting (p < 0.05).
* Corresponding author. Tel.: þ98 311 792 2024; fax: þ98 311 6687270. E-mail addresses:
[email protected] (J. Mostamand),
[email protected] (D.L. Bader),
[email protected] (Z. Hudson). 1360-8592/$ - see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.12.004
Reliability testing of the patellofemoral joint reaction force
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Conclusion: The high reliability of PFJRF measurements reveals that the future studies could rely on these measurements during single leg squatting. ª 2010 Elsevier Ltd. All rights reserved.
Introduction Patellofemoral pain syndrome (PFPS) is the most common diagnosis when there is knee joint pain in the young adults (Crossley et al., 2002). It is hypothesized that the biomechanics of the patellofemoral joint (PFJ), that is kinetic function, is affected in subjects with PFPS. It is also hypothesized that the values of this parameter will be different in PFPS subjects compared to subjects with asymptomatic knees. Alterations in patellofemoral joint reaction force (PFJRF) may therefore explain the cause of pain during a wide range of physical activities in subjects with PFPS. Treatment of PFPS is mostly based on physical therapy interventions (Crossley et al., 2002). Patellar taping is one of the treatment options, which is reported to reduce the pain immediately after its application in subjects with PFPS (McConnell, 1986; Bockrath et al., 1993; Powers et al., 1997; Ng and Cheng, 2002; Salsich et al., 2002). It is hypothesized that reducing pain following application of tape is related to altering PFJRF in PFPS subjects. Measuring PFJRF may therefore reveal whether the pain relief is associated with altering this parameter during functional activities. However, the reliability of PFJRF measurement during different activities and in different subject groups has not yet been reported. Accordingly, the aim of the present study is to examine the reliability of PFJRF in taped and untaped patellofemoral conditions during single leg squatting in healthy subjects. The future studies on the PFJRF values would be much more reliable in the symptomatic subjects if the results show that the reliability of PFJRF measurement is high enough during functional activities in healthy subjects.
Methods
extremities or the spinal column. They were also required to perform a single leg squat on repeated occasions.
Instrumentation Using a 2 camera (DCR-VX2000E, Sony, Japan) motion analysis system (SIMI Motion-2D&3D Motion Analysis, version 7.0, GmbH, Germany) and one forceplate (Kistler, 2812A-3, version 3.20, Switzerland), three dimensional movement and ground reaction force data of the subjects were recorded. Data were collected from superficial reflective markers taped to bony landmarks (Wallace et al., 2002). The five landmarks were the second metatarsal head, lateral malleolous, lateral aspect of the shank, lateral epicondyle of the femur and lateral aspect of the thigh, as illustrated in Figure 1.
Test procedure Before starting the main tests, all subjects were trained in how to perform single leg squats on their right legs, according to the required degrees of knee flexion, using verbal feedbacks (zero to approximately 45 degrees of knee flexion). To control any trunk forward flexion or deviation, they were asked to keep their feet in full contact with the floor during single leg squatting, while verbal feedback was used to encourage subjects to hold their trunks in a vertical position. After that, each subject was instructed to stand on their right leg on the forceplate and to keep the contralateral leg off the floor, as indicated in Figure 1. Each subject was then required to execute three shallow single leg squats, from 0 degree of the knee flexion to approximately 45 degrees of knee flexion. Subjects were subjected to three test conditions, namely, shallow single leg squatting before application of the tape (BT), with tape (WT) and a final test with no
Subjects The present study was approved by the East London and City Research Ethics Committee before recruiting subjects. Written informed consent was provided by each subject. The study was designed to examine the effects of taping on the patellofemoral joint of healthy subjects, and the reliability of outcome measurement (PFJRF) during single leg squatting. For this, eight healthy volunteers were recruited into the pilot study. These volunteers had no traumatic, inflammatory or infectious pathology in their lower extremities. Subjects with any history of surgery to their knees or dislocation or subluxation of their patellofemoral joints were also excluded from the study. Additionally, age greater than 40 years was one of the exclusion criteria to ensure subjects had no signs of secondary osteoarthritis (Crossley et al., 2002). The subjects, selected from students studying at Queen Mary University of London, had no previous history of disorders in either the lower
Figure 1 squatting
Setup used to measure kinetics during single leg
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tape (Shortly after tape Z SAT) on each testing occasion. This was conducted over three separate testing sessions. Each test session was performed with a minimum 6 h interval between them. Thus each subject executed 9 repetitions of single leg squatting at the end of the test procedure. Squatting was limited to about 3 s in duration, which was monitored by a stop watch. Patellar taping was employed to alter the alignment of the PFJ. Non-rigid, hypoallergenic tape (5 cm width, Sterofix hypoallergenic tape) was used to provide skin protection and rigid sterotape zinc-oxide tape (4 cm width, Steroplast Ltd Bredbury, England) was used for taping alteration. The taping technique involved employing a medial glide across the patella (Figure 2) according to the protocol described by McConnell (1986). As this technique is used in most subjects with PFPS to correct their lateral patellar glide (McConnell, 2002), the researcher used a similar technique in healthy subjects.
Data reduction Marker-coordinate and force data were processed by the SIMI motion analysis system. Using this system, the segmental kinematics for the foot, shank and thigh were computed. The inertial properties for the foot, shank and thigh were determined from the subject’s total body weight, segment geometry and anthropometric data (Winter, 1990). Sagittal-plane knee joint angles and net knee moments (Mk) were calculated from the inertial properties, segmental kinematics, and force platform data using inverse dynamics equations (Winter, 1990). The PFJRF was calculated using a biomechanical model of the PFJ (Salem and Powers, 2001). Based on the model, quadriceps muscle force (Fq) was calculated as the net knee moment (Mk) divided by the moment arm for the quadriceps (Lq). Fq ZMk =Lq The moment arm was estimated using the following nonlinear equation, based on the curve fitting to the data of van Eijden et al. (1987): Lq Z8:0e5 X 3 0:013X 2 þ 0:28X þ 0:046
where, X is the tibiofemoral joint angle. PFJRF was calculated as the product of the quadriceps force (Fq) and a constant (k) as follow: PFJRFZFq $k The constant k was estimated for knee joint angle (X ) using the following non-linear equation, based on the curve fitting to the data of van Eijden et al. (1986): 3:8e5 X 2 þ 1:5e3 X þ 0:462 kZ 7:0e7 X 3 þ 1:6e4 X 2 0:016X þ 1 For each test, kinetic data (Mk, PFJRF) were averaged through the 3 repetitions of single leg squatting. Data were analyzed in the eccentric phase of this activity at 30 degrees of knee flexion.
Data analysis All data were analyzed (SPSS-version 13) during the eccentric phase of squatting at 30 degrees of knee flexion. The ShapiroeWilk test was applied to all data sets (3 different sessions) of PFJRF measurements to test for normality. All data sets were found to be normally distributed and hence parametric statistics were used. Using the ANOVA test, the mean differences of PFJRF measurements during three different test sessions with 95% CI were calculated. From the mean and standard deviation of each data set, the coefficient of variation (CV) was used to describe the repeatability of the PFJRF measurements, for each subject and test. Random two-way intra class correlation coefficients for a single measure (ICC type 2, 1) were also used to examine whether the corresponding values of PFJRF during three different tape conditions (within session tests for three conditions of BT, WT and SAT) exhibited significant correlation. Additionally two statistics were calculated namely, 1. The within session least significant difference (LSD) values of PFJRF for the three different test sessions 2. The within session standard error of measurement (SEM) values of PFJRF for the three different test sessions
Results
Figure 2
Medial glide taping technique to alter the PFJ
Healthy volunteers (5 men and 3 women) with a mean age of 29.10 5.65 years were included in the study. A mean weight of 72.33 9.40 kg and a mean height of 168.20 8.25 cm were also obtained from these subjects. Summarized kinetic data of these subjects during eccentric phase of single leg squatting at 30 degrees of knee flexion are shown in Table 1. This data, relating to the right knees before, during and shortly after patellar taping, reveals few systematic trends for any of the parameters between the three tape conditions. ANOVA test revealed that, there were no significant differences between the PFJRF mean values for three conditions of BT, WT and SAT (p > 0.05).
Reliability testing of the patellofemoral joint reaction force
505
Table 1 Summarized data of three kinetic parameters measured on a group of 8 healthy subjects during the eccentric phase of single leg squatting at 30 degrees of knee flexion in 3 different conditions of before tape (BT), with tape (WT) and shortly after tape (SAT). Data represents mean SD.
BT WT SAT
Knee extensor moment (N m)
Quadriceps force (N)
PFJRF (N)
119.65 25.90 115.40 29.45 117.75 37.70
2645.20 560.25 2565.50 640.40 2615.35 705.65
2100.55 455.25 2026.20 516.45 2055.35 669.30
CV values The repeatability of the PFJRF measurements as determined from the values of CV is presented in Figure 3. It reveals that the minimum and maximum values for CV are 0.74% and 11.48%, respectively. For the majority of the cases (19 out of 24) the CV was less than 5%, indicating high repeatability of the PFJRF measurement during single leg squatting.
ICC values An analysis of the data using ICC, revealed relatively high intratester reliability for single measures of the PFJRF between three different repetitions (within session repetitions) of first (BT), second (WT) and third (SAT) test sessions. The minimum and maximum ICC values calculated for different repetitions in BT condition were 0.89 and 0.94, respectively. The values of 0.91 and 0.93 were also calculated as the minimum and maximum ICC values of WT condition. The minimum and maximum ICC values calculated for different repetitions in SAT condition were 0.90 and 0.95, respectively.
LSD values
Coefficient of variation of PFJRF (%)
Using the t value at a 5% significance level, the PFJRF LSD values of within session repetitions for the first test session (BT) were between 28.70 N and 64.95 N. The values of LSD for second test (WT) were also between 22.42 N and 57.62 N. Based on the results, the values of 20.82 Ne67.00 N were obtained from the third test (SAT) as reaction force LSD values. As there was no significant difference between each paired repetitions (p > 0.05) 15 10
BT WT SAT
5 0
S1 S2 S3 S4 S5 S6 S7 S8 Different tape conditions in healthy subjects
Figure 3 CV of the PFJRF during eccentric phase of single leg squatting (BT Z before taping, WT Z with tape and SAT Z shortly after taping) at 30 degrees of the knee flexion in eight healthy subjects (S)
these minimal differences reject the effect of random chance in obtaining similar results during within session repetitions, revealing accuracy of the results.
SEM values The SEM values of PFJRF during different test repetitions in different test conditions for 95% of probability were calculated. The SEM values of within session repetition for: first test session (BT) was between 233.0 N and 239.5 N second test session (WT) was between 263.0 N and 270.0 N third test session (SAT) was between 338.5 N and 341.0 N. These values indicated that the repeated measures (within session repetitions) fall between 2 SEM of initial measurement during these three different test conditions, demonstrating that the differences between repeated measures were not clinically relevant.
Discussion The CV values obtained from this study were low (majority of the values less than 5%) during within session tests in 3 different tape conditions, revealing high repeatability of PFJRF measurements (Figure 3). Indeed, these low scattered variabilities showed that the repeatability of PFJRF measurement is high during single leg squatting. The three tape conditions did not appear to influence the CV, revealing attachingereattaching of markers on the bony landmarks in different times, taping the patellofemoral joint or calibration of motions could not influence the results during different conditions. The ICC values of within session measurements of PFJRF during 3 conditions of BT, WT and SAT showed high reliability of the measurements. The high reliability of the PFJRF measurements during single leg squatting may reflect appropriate balance holding of the subjects during this activity. Clearly, the reliability tests using the ICC revealed that measuring the PFJRF during single leg squatting can be performed with high reliability in the future. The multiple comparison tests of PFJRF measurements in this study revealed that the measured differences of all paired mean values (within test sessions) were below the level of LSD values. This indicated that there was insufficient evidence to conclude testeretest values are different, revealing accuracy of each paired measurements. The relatively low values of within session SEM during this study, revealed that the random error of measurements were low, showing high precision of the PFJRF
506 measurements during 3 different conditions of BT, WT and SAT.
Conclusion The high reliability of PFJRF measurements using CV, ICC, LSD and SEM values reveals that future studies could rely on these measurements during single leg squatting.
Conflict of interest statement We confirm that authors have no conflict of interests regarding this paper.
Acknowledgement This article was provided as a part of the study leading to the degree of PhD, which was financially supported by Isfahan University of Medical Sciences and Ministry of Health and Medical Education of Islamic Republic of Iran.
References Bockrath, K., Wooden, C., Worrell, T., et al., 1993. Effects of patella taping on patella position and perceived pain. Medical Sciences and Sports Exercises 25, 989e992. Crossley, K., Green, S., Cowan, S., et al., 2002. Physical therapy for patellofemoral pain: a randomized, double blinded, placebo-
J. Mostamand et al. controlled trial. The American Journal of Sports Medicine 30 (6), 857e865. McConnell, J., 1986. The management of chondromalacia patellae: a long-term solution. Australian Journal of Physiotherapy 32 (4), 215e223. McConnell, J., 2002. The physical therapist’s approach to patellofemoral disorders. Clinics in Sports Medicine 21, 363e387. Ng, G.Y.F., Cheng, J.M.F., 2002. The effects of patellar taping on pain and neuromuscular performance in subjects with patellofemoral pain syndrome. Clinical Rehabilitation 16 (8), 821e827. Powers, C.M., Perry, J., Hsu, A., et al., 1997. Are patellofemoral pain and quadriceps femoris muscle torque associated with locomotor function? Physical Therapy 77 (10), 1063e1075. Salem, G.J., Powers, C.M., 2001. Patellofemoral joint kinetics during squatting in collegiate women athletes. Clinical Biomechanics 16, 424e430. Salsich, G.B., Brechter, J.H., Farwell, D., et al., 2002. The effects of patellar taping on knee kinetics, kinematics, and vastus lateralis muscle activity during stair ambulation in individuals with patellofemoral pain. The Journal of Orthopaedic and Sports Physical Therapy 32 (1), 3e10. van Eijden, T.M.G.J., Kouwenhoven, E., Verburg, J., et al., 1986. A mathematical model of the patellofemoral joint. Journal of Biomechanics 19 (3), 219e229. van Eijden, T.M.G.J., Weijs, W.A., Kouwenhoven, E., et al., 1987. Forces acting on the patella during maximal voluntary contraction of the quadriceps femoris muscle at different knee flexion/ extension angles. Acta Anatomica 129, 310e314. Wallace, D.A., Salem, G.J., Salinas, R., et al., 2002. Patellofemoral joint kinetics while squatting with and without an external load. Journal of Orthopedic Sports Physical Therapy 32 (4), 141e148. Winter, D.A., 1990. Biomechanics and Motor Control of Human Movement, second ed. A Wiley-Interscience Publication.
Journal of Bodywork & Movement Therapies (2011) 15, 507e516
available at www.sciencedirect.com
journal homepage: www.elsevier.com/jbmt
CLINICAL METHODS
A prophylactic effect of proprioceptive neuromuscular facilitation (PNF) stretching on symptoms of muscle damage induced by eccentric exercise of the wrist extensors Peanchai Khamwong, Ubon Pirunsan, Aatit Paungmali* Neuro-Musculoskeletal and Pain Research Unit, Department Physical Therapy, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand 50200 Received 8 September 2009; received in revised form 23 June 2010; accepted 19 July 2010
KEYWORDS Delayed onset muscle soreness; Range of motion; Strength; Pain threshold; Stretching; Prevention
Summary Stretching with proprioceptive neuromuscular facilitation (PNF) is frequently used before exercise. The prophylactic effect of PNF on symptoms of muscle damage induced by eccentric exercise of the wrist extensors was examined in this study. Twenty-eight healthy males were randomly divided into the PNF group (n Z 14) and the control group (n Z 14). PNF was used before eccentric exercise induction in the wrist extensors. All subjects were tested to examine muscle damage characteristics including sensory-motor functions at baseline, immediately, and from 1st to 8th days after the exercise-induced muscle damage (EIMD). The results demonstrated that the PNF group showed a lesser deficit in some sensory-motor functions (p < 0.05) than the control group. The prior PNF stretching application could be useful for attenuating the signs and symptoms of muscle damage after eccentric exercise. ª 2010 Elsevier Ltd. All rights reserved.
Introduction Muscle damage occurring after unaccustomed activities or high-intensity exercise is a common physiological occurrences in daily life. Exercise-induced muscle damage (EIMD)
* Corresponding author. Tel.: þ66 53 949246; fax: þ66 53 946042. E-mail address:
[email protected] (A. Paungmali).
can cause several types of muscle pathologies such as muscle strain, cramp and soreness (Miles and Clarkson, 1994). Delayed-onset muscle soreness (DOMS) is a common neuromuscular condition that affects individuals the day after they perform vigorous or unaccustomed exercises. Eccentric muscle contraction has been reported to induce muscle damage (Miles and Clarkson, 1994; O’Connor and Hurley, 2003). The symptoms of DOMS usually decline within a week. However, when the symptoms of muscle damage happen in patients during
1360-8592/$ - see front matter ª 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.07.006
508 a rehabilitation period, or in athletes, this may possibly interrupt the rehabilitation/training programs, along with sports performance, because of neuromuscular deficits. Many researchers have examined various ideas about intervention to reduce or prevent the severity of this kind of muscle damage. From a clinical perspective, preventative intervention is preferable and more important because it reduces the cost of treatment, time lost from training or rehabilitation, and the probability of persisting further injury. It also allows the continuation of exercise and competition (O’Connor and Hurley, 2003; Weerapong et al., 2004). Some useful methods to prevent musculoskeletal injuries include traditional interventions such as therapeutic exercise. In clinical practice, for example, we usually do stretching before the exercise as a preventative technique of muscle damage. It has been thought that the compliant muscle can be stretched further before it is damaged during eccentric exercise (Noonan et al., 1993; Safran et al., 1988) or that stretching could reduce muscle spasm after unaccustomed exercise (Herbert and de Noronha, 2007). Studies however have not shown the effectiveness of static stretching in the prevention of EIMD (High et al., 1989; Johansson et al., 1999). Rodenburg et al. (1994) reported that an intervention involving warm up, stretching and massage produced a significant reduction in muscle soreness. This study investigated the effects of a combination of interventions, so it could not provide an estimate of the specific effect of the stretching, in isolation from the other methods employed. However, Howatson and van Someren (2008) highlighted that other as yet uninvestigated stretching protocols, for example proprioceptive neuromuscular facilitation (PNF) may be of benefit, and therefore present a direction for further research. PNF stretching techniques are commonly used in the athletic and clinical settings to enhance both active and passive range of motions with a view to optimizing motor performance and rehabilitation. PNF stretching is one of the most effective stretching techniques which has been claimed to increase muscle flexibility (Sharman et al., 2006; Spernoga et al., 2001). There was also a report using a single set of PNF stretching which demonstrated a significant increase in flexibility (Spernoga et al., 2001). Improving tissue flexibility has also been mentioned as a means to reduce the risk of soft tissue injury and prevent muscle damage (O’Connor and Hurley, 2003; Weerapong et al., 2004). However, PNF technique has not yet been evaluated in patients with EIMD and it may prove that the use of PNF could have some potential benefit as a prophylactic effect. Much of the research on preventive damage and treatment of damaged muscles, has tended to use the group of big muscles as the model of muscle damage, for example, the biceps and the quadriceps (Nosaka et al., 2004; Sellwood et al., 2007). Other muscle groups, however, perform a range of different functions and respond to EIMD in different and diverse ways (Miles and Clarkson, 1994; Byrne et al., 2004; Jamurtas et al., 2005). The forearm muscle is an important muscle for daily activities and sports such as grasping, carrying, and sport activities which use a racquet such as tennis and squash. Limited research has been studied into the effects of PNF in the forearm extensor muscle. Therefore, the objective of this present
P. Khamwong et al. study was to understand the effect of PNF stretching on exercise-induced muscle damage in the wrist extensor muscle and determine its preventative effects.
Methods Participants Since gender and menstrual cycle influence the degree of EIMD (Dannecker et al., 2003), we conducted the study using only males. Based on a pilot study, the primarily clinical outcomes of EIMD (i.e., PPT, ROM-AE, pain-free GS and WES) were chosen to calculate the sample size. To obtain the power of 80% at the alpha level of 0.05 with the effect size of greater than 1.057, total sample size estimation would be approximately 14 subjects per group (Portney and Watkins, 2000). Demographic data of twentyeight healthy male volunteer students were presented as mean and SD (in brackets); age: 20.8 (1.3) years, height: 173.1 (4.7) cm, body weight: 61.9 (8.5) kg. They had no history of upper limb musculoskeletal disorders, neurological disorders, or any diseases that might affect the measurements prior to the study and had no experiences of arm resistance training at least 3 months before the study.
Outcome measures The non-dominant arm was used in this study to minimize possible effects of daily activities on the measures. The outcome measures consisted of pain intensity on a visual analogue scale (VAS) and modified Likert’s scale (LS), pain thresholds including thermal pain threshold [i.e., cold pain threshold (CPT)] and pressure pain threshold (PPT), range of motion in active wrist flexion (ROM-AF), active wrist extension (ROM-AE), passive wrist flexion (ROM-PF), and passive wrist extension (ROM-PE), grip strength (GS), wrist extension strength (WES) (Slater et al., 2003, 2005; Wright et al., 1994; Reese and Bandy, 2002). The order of measurements was pain intensity, CPT, PPT, ROM-AF, ROMAE, ROM-PF, and ROM-PE. Muscle strengths were measured after these measurements with a balanced randomization between GS and WES. Subjects were requested to participate in 11 experimental occasions to complete the study, and the travelling fee was reimbursed for all subjects. At the preliminary session all subjects who had agreed to take part, were familiarized with the purposes of the study and procedures. For baseline period, subjects were assessed for the dependent variables (all pain perceptions and motor functions) before the EIMD, and then evaluated for symptoms immediately and at follow up 8 days after the induction. The dependent variables were measured repeatedly at the same time of day. The CPT, PPT, ROM, and muscle strength were assessed three times to counteract variation between trials (Wright et al., 1994). To facilitate tissue recovery, 30 s interval between trials was allowed for measurements of CPT, PPT and ROM (Wright et al., 1994). For the measurement of muscle strength a 60 s rest interval was employed to avoid muscle fatigue (Slater et al., 2005). The mean value of the 3 trials was used for further analysis (Wright et al., 1994). The same
A prophylactic effect of proprioceptive neuromuscular facilitation stretching investigator conducted all measurements in a single-blinded manner. The room temperature was set at 25.0 C. All outcome measures including CPT, PPT, ROM (ROM-PF, ROMPE, ROM-AF, ROM-AE) grip and wrist extension strength, were considered to be reliable with a 24-h interval of testretest (ICC > 0.85) (Khamwong et al., 2010).
Study procedures Study design was a mixed model, 1 between (group) by 1 within (time) with a randomized-controlled experimental design. The subjects were divided into 2 groups (14 subjects per group). The control and experimental groups were arranged by chance using randomized drawing lots of 28 opaque sealed envelopes. The experimental group in this study obtained the application of PNF stretching before muscle damage induction, and the control group received muscle damage induction only. The study was approved by the institutional ethics committee and written consent was obtained from each subject.
PNF The PNF technique (hold-relax with agonist contraction) was performed for stretching. Each subject was asked to sit on an adjustable-height chair with supporting arm and then to move the hand beyond the edge of the supporting surface. The legs were set in a position of 90 hip-kneeankle, feet on the ground. The same chair and posture were applied for all subjects throughout the study. To standardize stretching method for the stretching group, the investigator passively stretched the wrist extensor muscles of the testing arm until each subject reported a mild stretch sensation and held that position for 10 s. Next, each subject was required to (isometrically contract the wrist extensor muscles to its maximum capacity) for 7 s by attempting to push his wrist back against the resistance of the investigator. After the contraction, each subject was allowed to relax for 5 s. Each subject was then asked to actively stretch the muscle, thus adding to the stretch force until a new point of mild stretch sensation was reached. The stretch was held for another 20 s (Figure 1). This sequence was repeated 10 times by each subject in the experimental group. This number of repetitions was chosen
509
as recommended by the literature and also to replicate the clinical use (Baechle and Earle, 2000; Spernoga et al., 2001).
Exercise induction The eccentric exercise protocol used the isokinetic mode of the Contrex dynamometer (CON-TREX Multijoint System, CMV AG manufacture, Switzerland). Subjects were placed in a seated position with support for the arm to be tested, to enable maximum resistance in the dynamometer’s movement from wrist extension to wrist flexion (Figure. 2). The exercise induction consisted of 5 sets of 60 maximal effort eccentric contractions of the wrist extensors at a velocity of 25 /s. A 1-min rest period between each set was allowed to counteract the effects of fatigue (Slater et al., 2005).
Pain intensity The visual analogue scale (VAS) was used to rate the intensity of pain. The VAS consisted of a 10 cm line anchored with “no pain” on the left end and “extreme pain” on the right end. Subjects were asked to rate their perceived level at pain at rest. A modified version of the Likert scale (LS) was also used to rate the level of muscle soreness as follow (Slater et al., 2003): 0 Z a complete absence of soreness; 1 Z a light soreness in the muscle felt only when touched/a vague ache; 2 Z a moderate soreness felt only when touched/a slight persistent ache; 3 Z a light muscle soreness when lifting objects or carrying objects; 4 Z a light muscle soreness, stiffness or weakness when moving the wrist without gripping an object; 5 Z a moderate muscle soreness, stiffness or weakness when moving the wrist; 6 Z a severe muscle soreness, stiffness or weakness that limits my ability to move. Thermal pain threshold (TPT) Cold pain threshold was assessed in the unit of degree Celsius ( C) using a Thermal Sensory Analyzer (Medoc Ltd., Neuro Sensory Analyzer Model TSA-II, Ramat Yishai, Israel). The measurement site was the belly of the extensor group muscles located at the prominent site over the carpi radialis brevis muscle. Subjects lay down on their backs with
Figure 1 The PNF stretching technique (hold-relax with agonist contraction) was performed by the investigator passively stretched the wrist extensor muscles until the subject reported a mild stretch sensation and held that position for 10 s. Next, the subject was asked to contract the wrist extensor muscles isometrically against the resistance of the investigator for 7 s. Then, the subject was asked to actively stretch the muscle until a new point of mild stretch sensation was reached.
510
P. Khamwong et al.
Figure 2 An eccentric exercise induction was performed using isokinetic mode of the Contrex dynamometer (CON-TREX Multijoint System, CMV AG manufacture, Zurich, Switzerland). The exercise induction consisted of 5 sets of 60 maximal effort eccentric contractions of the wrist extensors at a velocity of 25 /s.
arms by the side (0 elbow extension and 90 pronation). The thermode (5 cm2) was applied on the marked areas with Velcro strap for holding it in place. Using the standard protocol for evaluating TPT in wrist extensors, previously referred to, the initial temperature for testing cold pain threshold (CPT) was set up at 32 C. The thermode temperature was gradually decreased, by approximately 2 C/s each time to a minimum cut-off temperature of 0 C (Wright et al., 1994). Subjects held a control switch, and were instructed to press the button when they felt the sensation changing from cold to pain. Subjects received a verbal instruction approximately 1e2 s before the initiation of each test. Pressure pain threshold Pressure pain threshold (PPT) was measured in the unit of kilopascal (kPa) using a pressure algometer (Somedic Production, Algometer type II, Ho ¨rby, Sweden) with a probe of 1.0 cm2. PPT was assessed at the same muscle site as the measure of CPT. Subjects lay down on their backs with their arms by their side (0 elbow extension and 90 pronation). The probe was pressed at the reference site, and the pressure was increased at a rate of 30 kPa/s until subjects felt the sensation changing from the pressure to pain, which was indicated by the subjects pressing a button (Slater et al., 2005). Range of motion (ROM) ROM was evaluated in the unit of degree using a universal goniometer (SFTR International Standard Goniometer, Sammons Preston Healthcare, Bollingbrook, Illinois, USA) for wrist extension and flexion to determine the pain-free active and passive range of motions. Subjects sat on an arm supporting chair, and were asked to rest their arms on the support. The center of the goniometer was placed at the center of the axis of the wrist joint (triquetrum bone), and the angle parallel to the lateral midline of the ulna and the lateral midline of 5th metacarpal bone (Reese and Bandy,
2002). The pain-free active range of motion was performed by instructing the subject to move the wrist into flexion and extension directions, the subject was requested to stop the movement when first perceiving pain. For the pain-free passive range of motion, the subject was asked to relax the hand during passive movement of the wrist joint into flexion and extension directions by the investigator. The subject signaled the investigator for a position of the wrist when initial perceiving pain. Grip strength Grip strength (GS) was measured in Newtons (N) using an electronic digital hand dynamometer (Model MLT003/D, Power lab, Castle Hill, NSW, Australia). Subjects sat on a chair with their arms supported by a platform, which was set at the same length as from the elbow to the wrist joint. The upper extremity was positioned according to the recommendations of the American Hand Society of Hand Therapist (Fess, 1992) such that the shoulder was adducted and neutrally rotated, forearm in neutral position, and wrist slightly extended (20 ). GS was measured with the elbow in 90 flexion and within the comfortable grip width of each subject. The subjects were requested to grip as strongly as they could without pain (i.e., pain-free GS) and they were also instructed to perform a sustained maximal isometric contraction for 6 s (i.e., maximal GS) (Kamimura and Ikuta, 2001). Wrist extension strength Wrist extension strength (WES) was recorded via a force transducer (Model MLT003/D, Power lab, Castle Hill, NSW, Australia) in Newtons (N). A specifically designed pad hand attachment was connected to the underside of the force transducer. The transducer was mounted on a platform, which was located under the table. Each subject sat on a chair with his forearm in full pronation with 45 elbow flexion supported on an armrest of the chair, and his wrist was set in 20 extension with the 3rd knuckle placed to the
A prophylactic effect of proprioceptive neuromuscular facilitation stretching center of the force transducer. The subjects were requested to extend the wrist by pushing the dorsal surface of the hand on to the padded surface of the hand attachment as strong as they could without pain (i.e., pain-free WES) and they were also instructed to maximally extend the wrist against the dynamometer and sustained a maximal isometric contraction for 6 s (i.e., maximal WES) (Kamimura and Ikuta, 2001).
Statistical analyses Results of peak torque, total work and all outcome measures were expressed as mean and SD. Both absolute and “normalized” data were used for analysis of selected criterion measures. In case of pain intensity, VAS and LS were analyzed with absolute values. For CPT, PPT, and ROM, the “normalized” values refer to changes from preexercise values. In terms of muscle strength (GS and WES), the “normalized” values refer to percentages of pre-exercise values (i.e., normalized to pre-exercise). Outcome measurements, such as GS, WES, ROM, VAS, LS, CPT, PPT, were compared with the baseline values. The results were analyzed by the Statistical Package for the Social Sciences (SPSS) using repeated-measures ANOVA, followed by paired t-test pairwise comparisons with pre-specified contrasts to maintain experiment error rate below 5%. To test for the differences between groups at each time period, an ANOVA for independent observations was used. Statistical significance was set at 0.05 for all analyses.
Results Subject characteristics The subjects were arranged by chance into the control and the experimental groups using randomized drawing of lots. Mean differences between groups of the subjects’ characteristics (i.e., age, height, weight) were less than 3%, considering no differences in statistical and clinical aspects (Table 1). No significant differences in the baseline values between groups were observed for any of the dependent variables except for PPT (Table 1). Normalized data were used to adjust a variation among individual subjects.
Peak torque and total work during eccentric exercise All subjects were able to complete each set of the exercise induction protocol. No significant differences in mean
511
maximal torque and total work during the eccentric exercise were evident between the control and PNF groups (Table 1).
Pain intensity Pain intensity was assessed by visual analogue scale and muscle soreness using Likert’s scale. In the control group, pain intensity of VAS was significantly increased when comparing the pain level at pre-exercise to immediately post-exercise, and days 1e6, post-exercise (p < 0.044). In the PNF group, the VAS was significantly increased when comparing the pain level at pre-exercise to immediately post-exercise and days 1e4 post-exercise (p < 0.008). LS was significantly increased as the similar manner of VAS at immediately post-exercise and days 1e6 post-exercise in the control group (p < 0.026) and immediately post-exercise and days 1e5 post-exercise in the PNF group (p < 0.022). The difference in pain intensity between control and PNF were not statistically significant (Table 2).
Pain threshold Thermal pain threshold Cold pain threshold at muscle site was significantly increased when comparing the pain threshold at preexercise to days 1e3 post-exercise (p < 0.047) in the control group. CPT was not significantly different from the baseline in the PNF group. There was also a significantly lower deficit in CPT within the PNF group in comparison to the control group on days 1e5 post-exercise (p < 0.043) (Table 2). Mechanical pain threshold Pressure pain threshold at muscle site was significantly decreased from the baseline during an immediately postexercise and days 1e4 post-exercise (p < 0.048) in the PNF group; however, the PPT of the control group decreased significantly from an immediate post-exercise and did not return to the pre-exercise level by day 5 post-exercise (p < 0.011). The PNF group was significantly higher in PPT than the control group on day 8 post-exercise (p Z 0.016) (Table 2). Range of motion Range of motion was assessed in passive and active of flexion and extension. Passive range of wrist flexion was significantly decreased when comparing the range at preexercise to immediately post-exercise and days 1e8 postexercise in the control group (p < 0.013) and in the PNF
Table 1 Mean and standard deviation (in brackets) of subject’s characteristics (age, height, and weight) and work load during eccentric exercise induction. Characteristics
Control group (n Z 14)
PNF group (n Z 14)
Age (years) Height (cm) Weight (kg) Peak torque (N) Total work (J)
21.1 173.1 61.3 3.3 180.0
20.5 173.0 62.4 4.0 177.2
(1.6) (5.1) (9.6) (0.9) (56.6)
No clinically important differences between groups were evident for all data.
(0.9) (4.5) (7.6) (1.4) (60.0)
Changes in outcome measures before (pre), immediate (Imm) and 1e8 days following eccentric exercise of the PNF (n Z 14) and control (CON; n Z 14) groups. Pre
Imm
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
VAS (cm) CON 0 (0) PNF 0 (0)
2.5 (2.1)a 1.8 (2.0)a
4.8 (1.9)a 4.4 (2.5)a
5.0 (1.7)a 3.7 (2.4)a
3.2 (1.7)a 2.8 (2.4)a
2.0 (1.5)a 1.7 (2.0)a
0.8 (0.8)a 0.7 (1.2)
0.2 (0.4)a 0.2 (0.5)
0.0 (0.9) 0.0 (0.1)
0.0 (0.1) 0 (0)
LS (level) CON 0 (0) PNF 0 (0)
2.7 (2.1)a 1.3 (1.9)a
4.1 (1.5)a 4.9 (0.7)a
4.4 (1.6)a 4.6 (1.3)a
3.6 (1.8)a 3.6 (1.6)a
2.8 (1.8)a 2.1 (1.9)a
1.9 (1.7)a 1.6 (1.8)a
0.9 (1.4)a 0.4 (1.1)
0.1 (0.4) 0.3 (1.1)
0 (0) 0 (0)
CPT (oC) CON 0 (0) PNF 0 (0)
2.7 (4.8) 0.7 (3.8)
3.9 (6.6)a 0.7 (3.4)b
5.9 (7.8)a 0.3 (3.6)b
3.1 (5.3)a 0.7 (4.0)b
3.3 (6.1) 1.0 (3.3)b
2.6 (5.7) 1.5 (3.3)b
0.4 (4.7) 0.8 (2.8)
0.5 (5.6) 1.6 (3.2)
1.4 (6.7) 1.5 (2.5)
PPT (kPa) CON 0 (0) PNF 0 (0)
30.8 (39.2)a 50.6 (56.1)a
128.0 (95.8)a 126.5 (54.2)a
125.9 (96.5)a 123.1 (86.0)a
97.4 (84.0)a 88.3 (89.6)a
61.9 (60.7)a 43.6 (74.9)a
46.4 (55.6)a 16.5 (79.4)
15.6 (52.2) 10.8 (60.3)
8.2 (42.3) 33.1 (79.8)
2.2 (32.1) 44.6 (52.4)b
ROM-PF (degree) CON 0 (0) PNF 0 (0)
9.1 (10.5)a 8.9 (7.6)a
29.6 (12.2)a 18.4 (13.3)a,b
34.2 (14.5)a 21.7 (17.8)a
28.2 (15.6)a 19.3 (16.8)a
23.2 (14.5)a 15.7 (15.8)a
15.2 (9.5)a 9.4 (12.8)a
11.3 (9.2)a 9.1 (10.4)a
7.2 (6.3)a 5.9 (8.7)a
4.7 (6.1)a 6.0 (10.4)a
ROM-PE (degree) CON 0 (0) PNF 0 (0)
8.6 (7.7)a 3.0 (5.7)b
18.3 (9.8)a 7.2 (9.0)b
20.6 (16.4)a 4.4 (6.8)b
14.1 (13.3)a 1.4 (5.2)b
10.1 (11.8)a 1.5 (6.1)b
6.8 (9.7)a 2.4 (5.5)b
4.6 (8.1) 3.8 (6.9)b
2.6 (6.6) 2.9 (7.6)b
2.0 (7.3) 4.6 (5.6)b
ROM-AF (degree) CON 0 (0) PNF 0 (0)
9.9 (8.6)a 6.9 (4.9)a
17.1 (10.0)a 11.5 (10.3)a
21.1 (12.1)a 16.0 (13.0)a
15.9 (11.3)a 15.8 (16.9)a
13.6 (13.0)a 11.2 (13.5)a
6.1 (6.1)a 7.0 (9.5)a
2.8 (6.7) 5.6 (6.4)a
0.2 (8.1) 4.9 (6.1)a
2.1 (9.1) 4.0 (7.2)
20.5 (9.9)a 10.1 (8.8)a,b
19.5 (13.3)a 5.4 (6.3)a,b
12.6 (7.0)a 3.7 (7.5)b
8.5 (5.6)a 2.9 (8.5)b
4.3 (3.9)a 0.1 (5.4)b
4.3 (4.8)a 0.0 (5.0)b
2.5 (4.0)a 0.7 (5.2)
1.6 (3.7) 1.4 (4.3)
95.0 (15.5) 100.7 (12.0)
100.6 (16.5) 98.1 (12.5)
102.0 (14.8) 98.8 (14.6)
102.5 (17.5) 101.4 (16.8)
105.1 (16.3) 104.7 (17.8)
105.1 (14.2) 107.9 (17.4)
93.5 (18.3) 99.7 (16.7)
94.7 (18.3) 102.7 (15.7)
ROM-AE (degree) CON 0 (0) 25.8 (10.4)a PNF 0 (0) 17.2 (14.3)a GS [max] (N) CON 100 (0) PNF 100 (0)
74.4 (16.6)a 70.8 (13.8)a
90.6 (15.3)a 89.4 (11.1)a
94.9 (12.7) 95.9 (11.6)
GS [pain-free] (N) CON 100 (0) PNF 100 (0)
51.1 (19.5)a 52.2 (15.5)a
52.0 (24.5)a 66.7 (18.3)a
51.5 (24.4)a 76.5 (12.9)a,b
68.6 (27.1)a 85.3 (18.0)a
77.9 (17.5)a 89.1 (15.3)a
86.9 (16.8)a 93.3 (15.7)
88.6 (16.7)a 94.7 (14.4)
512
Table 2
P. Khamwong et al.
94.5 (23.7) 99.7 (18.7) 88.0 (21.7) 89.2 (17.5) 79.2 (19.8)a 92.1 (20.1) 75.4 (19.9)a 91.2 (18.2)a 70.8 (22.8)a 74.0 (22.4)a Data are presented as mean (SD). For GS and WES, the pre-exercise level was expressed as 100%. a Significantly different from the baseline (pre). b Significantly different from CON.
41.6 (23.8)a 71.1 (21.8)a,b 34.6 (13.5)a 57.2 (20.8)a,b WES [pain-free] (N) CON 100 (0) 38.2 (14.9)a PNF 100 (0) 44.6 (12.3)a
513
group (p < 0.049). ROM-PF did not return to the baseline values within 8 days post-exercise in both groups. The PNF group, however, demonstrated a significantly lesser deficit in ROM-PF values than in the control group on day 1 postexercise (p Z 0.028) (Table 2). Passive range of wrist extension was significantly decreased from the baseline at 1 and 2 days post-exercise (p < 0.032) in the PNF group; however, the ROM-PE of the control group decreased significantly from an immediate post-exercise and did not return to the pre-exercise level by day 5 post-exercise (p < 0.021). The PNF group significantly demonstrated a lesser deficit in ROM-PE than the control group at immediately post-exercise and on days 1e8 post-exercise (p < 0.049) (Table 2). There was no significant difference in ROM-AF between control and PNF groups. Active range of wrist extension was significantly decreased from the baseline during an immediately post-exercise and days 1e2 post-exercise (p < 0.007) in the PNF group; however, the ROM-AE of the control group decreased significantly from an immediate post-exercise and did not return to the pre-exercise level by day 7 post-exercise (p < 0.035). The PNF group significantly demonstrated a lesser deficit in ROM-AE than that of the control group on days 1e6 post-exercise (p < 0.048) (Table 2).
56.4 (27.7)a 74.6 (19.9)a
96.7 (19.7) 96.3 (18.1) 82.2 (34.9)a 87.1 (18.9)a WES [max] (N) CON 100 (0) PNF 100 (0)
63.6 (11.5)a 61.1 (14.0)a
67.3 (18.4)a 77.6 (13.3)a
86.7 (21.2)a 89.8 (21.7)
94.1 (16.0) 90.6 (18.7)
107.2 (27.0) 97.3 (20.4)
106.0 (28.1) 98.2 (20.9)
110.2 (28.4) 106.1 (24.5)
A prophylactic effect of proprioceptive neuromuscular facilitation stretching
Muscle strength Pain-free grip strength declined significantly from the baseline during an immediately post-exercise and days 1e4 post-exercise (p < 0.019) in the PNF group; however, the GS [pain-free] of the control group decreased significantly from an immediate post-exercise and did not return to the pre-exercise level by day 6 post-exercise (p < 0.023). The PNF group significantly demonstrated a lesser deficit in GS [pain-free] than the control group on day 2 post-exercise (p Z 0.002). There was no significant difference in GS [max] between control and PNF groups (Table 2). Pain-free wrist extensor strength declined significantly from the baseline during an immediately post-exercise and days 1e4 post-exercise (p < 0.001) in the PNF group; however, the WES [pain-free] of the control group decreased significantly from an immediate post-exercise and did not return to the pre-exercise level by day 6 postexercise (p < 0.002). The PNF group significantly demonstrated a lesser deficit in WES [pain-free] than that of the control group on days 1e2 and day 5 post-exercise (p < 0.037). There was no significant difference in WES [max] between control and PNF groups (Table 2).
Discussion The main findings of this study were the beneficial effects of PNF intervention on EIMD symptoms as set out in the following categories of sensory perception and muscle function.
Sensory perception The PNF group significantly demonstrated a lesser deficit in cold pain and pressure pain threshold than in the control group. We have demonstrated that using the PNF (hold-relax
514 with agonist contract) technique can help to minimize pain perception and reduce the effect of cold and pressure stimuli on CPT and PPT at the muscle site. It has been reported that a single bout of resistance exercise is capable of modifying the sensation of experimentally induced analgesia (Koltyn and Arbogast, 1998; Koltyn et al., 2001). Hoeger Bement et al. (2009) also reported that an isometric fatiguing contraction significantly alters the corticomotor pathway during application of a noxious stimulus. These insights help to explain why PNF intervention has some effect on the thermal and mechanoreceptor adaptation to these stimuli, as shown in the results from the PNF group when compared to the control group. Passive flexion range of the wrist demonstrated a lesser deficit in the PNF group. Passive extension range of the wrist in the PNF group also demonstrated fewer deficits. Muscle soreness is more painful and sensitive with stretching (Byrne et al., 2004). Passive range of motion can cause more pain especially in the opposite movement (i.e., flexion direction) of the damaged wrist extensor muscle and more compression of the muscle belly when moved in the same direction (i.e., extension direction) of the damaged muscle. The two directions of experiment lead to muscle guarding during the movement (Jones et al., 1987). This present study showed a greater reduction of ROM-PF and ROM-PE in the PNF group.
Motor function There was no significant difference in the active flexion range of the wrist between the control and the PNF groups. During the contraction of active flexion, reciprocal inhibition mechanism may take part to reduce tone of the wrist extensors when assessing the flexion range of motion (Guyton and Hall, 2006). This may be one reason why the measurement of active wrist flexion in this study has not shown any difference in ROM-AF between groups. Active extension range of the wrist in the PNF group demonstrated a lesser deficit than in the control group. Active movement (contraction) of a sore muscle can affect the excitation contraction coupling and cause pain during motion (Byrne et al., 2004). The PNF group demonstrated better passive and active wrist extension movements than in the control group. In general, EIMD can cause a reduction in the ROM due to pain or stiffness after exercise. Application of PNF has beneficial effects on active extension in this ROM measure. It seemed that pain-free muscle strength is more sensitive for detection of muscle damage than the maximal muscle strength test. The pain-free grip strength and wrist extensor strength in the PNF group have fewer deficits than the control group. Muscle strength is one of the best muscle damage indicators, which is normally reduced after exercise with slow recovery (Nosaka and Newton, 2002). The prevention of EIMD by using PNF has shown the beneficial effect on muscle strength of grip and wrist extension in this present study, as shown in a lower deficit of pain-free grip and wrist extensor strength. The result of our study was dissimilar to previous studies. High et al. (1989), Johansson et al. (1999) did not demonstrate the efficacy of stretching on muscle soreness in quadriceps and hamstrings, respectively. They applied
P. Khamwong et al. static stretching before the induction exercises in healthy student volunteers, and their results showed no effect of static stretching on EIMD. In this present study, a different stretching technique (PNF-hold-relax with agonist contraction) was performed. This technique is a combination of both static and dynamic stretching maneuvers. As a result, some advantageous effects of the PNF were evidenced on EIMD symptoms in terms of sensory perception and muscle function. The application of PNF before exercise was aimed at preparing the localized muscle to prevent EIMD symptoms. PNF technique of hold-relax with agonist contraction was used to prepare the wrist extensors with passive and active movement that can improve muscle flexibility via autogenic inhibition and reciprocal inhibition. The benefits of an active warm up may be to minimize muscle stiffness by moving the required muscle groups through their range of motion. As a result, the warm up with PNF stretching may release actin-myosin bonds and thereby reduce the passive stiffness of muscle. This may contribute to an increased rate of force development and an increase in the efficacy of muscle working during eccentric exercise (Bishop, 2003). Stretching exercises also affect the mechanical properties of the muscle-tendon unit (MTU), i.e., reduce the tension on the muscle-tendon unit that affects the visco-elastic component of tissue leading to an increase in the compliance of muscle and a reduction in muscle stiffness; consequently, less tension will be produced in the muscle during a specified stretch. The resulting improvement of muscular flexibility possibly reduces muscle and connective tissue damage after exercise (Weldon and Hill, 2003; Magnusson and Renstrom, 2006). Apart from the visco-elastic mechanism of PNF stretching, a neurophysiological mechanism may take part for the effects through neural inhibition of the muscle group being stretched via an inhibitory interneuron. As a result of reducing the activity in the alpha-motor neuron to the antagonist muscle, which then promotes greater relaxation and decreases resistance to stretch (Guyton and Hall, 2006). It is also possible that the descending pain inhibitory systems (e.g., mid brain) may be activated during PNF stimulation (Carrive, 1993). Further neurological studies, such as functional magnetic resonance imaging (fMRI), are warranted to investigate this notion. There remains a question regarding the clinical importance of the findings (i.e., CPT, PPT, ROM-PF, ROM-PE, ROMAE, GS and WES [pain-free]). As there is no information regarding this issue, we determined the clinical meaningfulness by estimating the minimally clinical important difference (MCID) using a distribution-based approach as recommended by Wells et al. (2001). The findings demonstrated that all of these observed changes were beyond the standard error of measurements (Khamwong et al., 2010), and the observed values were greater than 37% (i.e., changes in thermal pain, pressure pain, range of motion, and strength were 6.2 C, 42.4 kPa, 11.4 , 29.5 N, respectively). Therefore, we considered that these amounts of change were clinically meaningful for rehabilitation and sport performance. A limitation should be noted that the placebo condition was not included in the study. Studies in the future should consider the placebo-controlled study design for strengthening the internal validity of the study.
A prophylactic effect of proprioceptive neuromuscular facilitation stretching
Conclusion This study showed that PNF stretching prior to exercise can reduce the symptoms of muscle damage, especially pain threshold, ROM, and muscle strength. The PNF demonstrated a lesser deficit in both thermal and mechanical pain thresholds, pain-free muscle strength, passive ROM and active extension ROM than the control group. Results of this study suggests that applying PNF stretching prior to exercise help to attenuate symptoms of EIMD in the wrist extensors.
Acknowledgements The authors would like to express our gratitude to the participants and the Thai Health Promotion Foundation for funding this study.
Declaration of interest The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
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Journal of Bodywork & Movement Therapies (2011) 15, 517e524
available at www.sciencedirect.com
journal homepage: www.elsevier.com/jbmt
EXERCISE PHYSIOLOGY RESEARCH
Influence of dynamic versus static core exercises on performance in field based fitness tests Kelly L. Parkhouse, BSc, ASCC a, Nick Ball, PhD, ASCC, CSCS b,* a b
Department of Sport and Exercise Science, University of Portsmouth, UK National Institute of Sports Studies, Faculty of Health, University of Canberra, ACT 2601, Australia
Received 5 July 2010; received in revised form 16 November 2010; accepted 30 November 2010
KEYWORDS Lumbopelvic; Stability ball; Performance
Summary Minimal evidence supports the claim that core stability training transfers into improved performance and the most effective training method to perform core exercises is still unknown. The purpose of the study was to compare the effects of a 6 week unstable static versus unstable dynamic core training program, on field based fitness tests. A static (n Z 6) and dynamic (n Z 6) training group performed two 45 min sessions per week for six weeks. Seven performance tests, consisting of three core (plank; double leg lowering; back extensions), one static (standing stork) and three dynamic (overhead medicine ball throw; vertical jump; 20 m sprint), were administered pre- and post training. Between group differences were assessed using a repeated measures MANOVA (P < 0.05). Both training groups improved in each of the core tests (P < 0.05). Neither training group demonstrated improvement in the dynamic field based tests (medicine ball throw, vertical jump height and 20 m sprint) (P > 0.05). Findings indicate that both types of training improved specific measures of core stability but did not transfer into any sport-related skill. Crown Copyright ª 2010 Published by Elsevier Ltd. All rights reserved.
Introduction Core stability training on unstable surfaces is commonplace in both healthcare and conditioning settings. Proponents of unstable training argue that such training enhances neuromuscular pathways (Beache and Earle, 2000; Hedrick, 2000), leading to greater strength (Behm et al., 2005; Gamble, 2007; * Corresponding author. Tel.: þ61 (0) 2 6201 2419; fax: þ61 (0) 2 6201 5615. E-mail address:
[email protected] (N. Ball).
Rutherford and Jones, 1986; Vera-Garcia et al., 2000), power (Jeffreys, 2002) and balance (Anderson and Behm, 2005; Goodman, 2003; Lehman et al., 2005). Generally, findings have indicated that as the degree of instability increases, the degree of core muscle activity increases proportionally (Anderson and Behm, 2005; Behm et al., 2005; Marshall and Murphy, 2005; Murphy and Wilson, 1996; Vera-Garcia et al., 2000). For this reason, resistance exercises performed on unstable surfaces have been emphasized as most effective for the development of core stability (Boyle, 2004; Chek, 1999). Kibler et al. (2006) defined core stability as ‘the ability to control the position and motion of the trunk over the pelvis,
1360-8592/$ - see front matter Crown Copyright ª 2010 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2010.12.001
518 thereby allowing optimum production, transfer and control of force and motion to the terminal segment in integrated athletic kinetic chain activities’. The role of core muscles in movement is varied according to the dynamics and postural demands of a given activity (Brown, 2006; Rogers, 2006). The core region can be divided into local and global groups (based on location and attachment site) (Johnson, 2002). Local muscles consist of small, deep muscles that control intersegmental motion between adjacent vertebrae (Johnson, 2002) and act as ‘stabilizers’ (Carter et al., 2006). Global muscles are large, superficial muscles that transfer force between the thoracic cage and pelvis and play a role in creating movement (Carter et al., 2006). As the core is central to most kinetic chains in sports movements, control of core strength, balance and motion will maximize the kinetic chains of upper and lower extremity function (Kibler et al., 2006), resulting in more efficient, stronger and powerful movements (Hedrick, 2000; McCurdy et al., 2005). Hence, there is an assumption that an improved core will increase one’s ability to run, jump, throw, strike and swing. There are two primary types of core training; static and dynamic training. Static training involves the joint and muscle either working against an immovable force (maximal muscle action) or being held in a static position while opposed by resistance (sub-maximal muscle action) (Siff, 2004). Actions within a wide variety of sports require isometric strength; for example, climbing, mountain biking, Judo, wrestling, gymnastics and horseback riding (Stone et al., 2003). Dynamic strength is the ability to exert a muscle force concentrically or eccentrically repeatedly or continuously over time. Due to the body’s functional design, during dynamic movement there is more dependence on core musculature than just skeletal rigidity as in a static situation; as the purpose of movement is to resist a force that changes its plane of motion (Siff, 2004). The surface the core exercise is performed on can also be varied to attempt to stimulate increased core activation through increased proprioceptive demands compared to floor based exercises (Cosio-Lima et al., 2003). Dynamic exercises performed on unstable surfaces are unable to reproduce the force and power outputs found when performing the same exercise on a stable surface (Anderson and Behm, 2005; Carter et al., 2006; McGill, 2001; Scibek et al., 2001) thus questioning the use of performing conventional exercises on unstable surfaces to enhance the transfer of training effect for the prescribed movement. However the transfer of training effect of dynamic core exercises into dynamic movements has not been investigated. There is disagreement amongst coaches about which type of strength is preferably developed for optimal performance (Plamondon et al., 1999; Stone et al., 2003). Past research has shown a positive transfer of training effect of dynamic exercises to dynamic tasks and static exercise to static tasks for non-core musculature (O’Shea and O’Shea, 1989). Several investigators also suggest that isometric forceetime characteristics are poorly correlated with dynamic performance (Haff et al., 2005; Murphy and Wilson, 1996). This indicates a limited transfer of training of static core exercises to dynamic performance. The use of field based fitness tests is an easy and convenient assessment method to allow coaches and users to track and monitor progress following an intervention (Winter
K.L. Parkhouse, N. Ball et al., 2007). The assessment of further neuromuscular and kinetic adaptations or transfer would require the use of specific technology such as electromyography (Winter et al., 2007), linear encoders (Harris et al., 2010) and force platforms (Winter et al., 2007) which are not freely available. The purpose of the study was to compare the effects of a 6week unstable static versus unstable dynamic core stability training program on core strength and other performance variables. Based on the principle of specificity, we predict a positive transfer of training effect of dynamic core exercise to the dynamic based tasks and a positive transfer of training effect of static core exercise to the static based tasks.
Methods Experimental approach to the problem This study involved a two group, two factor design to address whether a static or dynamic core stability ball intervention improved core and field based performance tests. Factor one was test, which had two levels: pre- and post testing. Factor two was training, which also had two levels: static or dynamic group. Dependent variables included 3 measurements of core performance (a static plank and double leg lowering test and a dynamic back extension test), 3 dynamic performance tests for speed (20 m sprint), lower body power (vertical jump), upper body power (overhead medicine ball throw) and a static balance test (standing stork).
Participants A group of 12 participants (6 male: 21.2 3.3 years; 174.5 6.3 cm; 78.7 3.7 kg, 6 female: 20.6 1.7 years; 172.6 4.7 cm; 67.7 2.3 kg) volunteered for the study. Informed consent was obtained and health history questionnaires were completed. All participants competed in University level sport >8 h per week and reported no history of acute or chronic low back injury prior to this experiment. All participants had prior experience of core stability exercises but had never undertaken a prescribed core stability program. Participants were asked to refrain from any other form of core specific exercises during the training period. Before commencement, the University Ethics review board approved the study. Participants were randomly assigned to either the static or dynamic core stability training group ensuring an equal gender split in each group.
Testing procedures Participants were instructed on how to perform each test and were allowed a familiarization period. Participants recorded their assessed test no less than 3 min following the familiarization period. Sufficient rest of at least 10 min was given between each test. Participants were told to put in maximal effort throughout each test whilst maintaining the correct position of the lumbar spine, with correct technique overseen by a qualified strength and conditioning coach. The battery of seven tests were completed 1 week prior to the training interventions and repeated one week after the training interventions. All tests were randomised for each participant to minimize learning effects.
Influence of dynamic versus static core exercises on performance in field based fitness tests
Static core tests Plank Participants were required to lie face down on a mat with their forearms and toes on the floor. On command, participants were asked to raise their hips off the floor to form a straight line from the shoulders to the heels, with a neutral back. Tests commenced once the correct position was assumed and discontinued when the position changed. A demonstration was shown and teaching points emphasized. The test was timed (s) using a stopwatch. Double leg lowering Participants laid with their back on a mat and knees to chest. After contracting the core region, they slowly slid both legs out into a straight position, with feet remaining 5 cm off the floor at all times. Participants were instructed to keep a neutral back for the duration of the test. Tests were discontinued when the body position changed or when legs became less than 180 to the body. The test was timed (s) using a stopwatch.
Dynamic core test Back extensions Participants were required to lay face down with hands at the temples. The number of repetitions performed was recorded in 2 min. They were encouraged to avoid lifting the feet off the floor to avoid the gluteus maximus aiding the lower back. A back extensor endurance test was used rather than a common curl-up test because there is only very low correlation of curl-up tests with core strength and endurance (Knudson, 2001), whereas back extensor tests give a better indication of lumbo-pelvic stability and strength.
Static field based test Standing stork (balance) Participants stood with hands on hips and were instructed to lift 1 leg and place the sole of the foot on the inner thigh of the other leg. On command, participants raised the heel of the straight leg to stand on the toes. Participants were required to balance for as long as possible without the heel of the foot touching the ground, or the other foot moving away from the knee. The test was repeated on the other leg. The test was timed (s) using a stopwatch.
Dynamic field based tests Overhead medicine ball throw (upper body power) Participants were required to kneel with the back erect, facing the throwing direction with their knees just behind the start line. With a 4 kg medicine ball grasped in both hands, participants were instructed to bring the ball back over the head and in 1 motion, throw the ball forwards and upwards with maximal power. It was emphasized that the spine must not be rotated and the favored arm must not be used to throw the arm. Stockbrugger and colleagues (Stockbrugger and Haennel, 2001) have shown this test to be a valid and reliable test for assessing explosive core and upper body power.
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Vertical jump (lower body power) Vertical jump height was taken from a static position with both feet together. Participants were instructed to place both hands on their hips and upon a verbal signal selfselected their depth for the countermovement jump. Participants were required to jump vertically as high as they could. The jump height was recorded (cm) using a vertical jump meter (Takei, Japan). 20 m sprint (speed) A straight 20 m line was measured and marked with cones. Light gates (Brower, UK) were positioned at both 0 m and 20 m. Participants were asked to start with their feet behind the start cone and to perform the task maximally. On the commands ‘take your marks’ and then ‘go’ participants were asked to sprint towards and the time gates at the 20 m mark. Time (s) was recorded from the timing gates.
Training procedure Each training group was required to attend two 45 min training sessions per week with a three day gap between each session. Three days prior to the commencement of the first training session, participants completed a familiarization session to ensure they were comfortable with the procedures and to minimize any learning effects. During this they practiced the concepts of ‘drawing in’ (neutralizing the spine and working the transverse abdominis and multifidus), correct postural control, the importance of breathing (Carter et al., 2006; Gamble, 2007) and stability ball balance (Goodman, 2003). Each participant was given a ball that was in accordance to their height. The size of the ball was conducive to achieving >90 angle at both the hip and knee (Goodman, 2003). The stability balls were 55, 65 or 75 cm in diameter. At the start of each training session, participants completed a thorough 10 min warm-up which included exercises such as jogging, skipping, but kicks and side stepping, followed by static stretching and specific lumbo-pelvic mobility exercises to reduce injury risk and lower back pain. Stretching was also completed upon completion of each session. All participants in both training groups completed 6 exercises per session. Overload was provided in the forms of increased duration and frequency (sets, reps, time under tension), increasing the complexity of exercises (adding opposite limb movements), increasing the lever arm of the exercises, altering the base of support and increased loading (external weights) (Gamble, 2007) (see Tables 1 and 2). The static group used a duration of 20 s or more when using submaximal loads (such as body weight) and 8e10 s with external resistance. The dynamic group performed 16 or more repetitions when using sub-maximal loads and 8e12 repetitions with external resistance. Exercises are based on previous references for core exercise prescription and were considered safe and effective (Cissik, 2002; Goodman, 2003; Hedrick, 2000; Lehman et al., 2005; Plamondon et al., 1999; Stanton et al., 2004; Vera-Garcia et al., 2000).
Statistical analyses On the completion of data collection, statistical analyses comprised of descriptive statistics to identify means and standard deviations for each variable of interest. The initial
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K.L. Parkhouse, N. Ball
Table 1
Static core stability program. Exercise, frequency, duration and applied progression and overload for each week.
Exercise
Week 1
Week 2
Week 3
Week 4
Week 5
Week 6
a
Time e secs (sets) Instruction
Time e secs (sets) Progression Time e secs (sets) Progression Time e secs (sets) Progression
Time e secs (sets) Progression Time e secs (sets) Progression
Side planka
Shoulder bridge
Full plank
Birddoga
Diagonal cruncha
Reverse hyperextension
25 (2)
30 (2)
25 (2)
30 (2)
20 (2)
15 (2)
On elbow, Top arm by side 35 (2)
Arms to side, feet wide, knees bent 45 (2)
Knees dropped, on elbows
1 leg only
Hands on knees
Hands by side
35 (2)
40 (2)
30 (2)
25 (2)
Increase time 25 (2)
Forearms up, increase time 35 (2)
Increase time
Increase time
35 (2)
30 (2)
Increase time 25 (2)
Increase time 35 (2)
Top arm in air 25 (2)
1 leg straight
On elbows, legs straight 45 (2)
Opposite arm & leg 40 (2)
Hands on chest 35 (2)
Arms on chest 45 (2)
Both legs straight, heels on ball
Increase time
Increase time
Increase time
Increase time
40 (2)
40 (2)
30 (2)
30 (2)
30 (2)
Arms off floor, increase time 40 (2)
On hands with legs straight 45 (2)
Both arms and 1 leg 40 (2)
Hands by temples 40 (2)
Hands by temples 40 (2)
Lift 1 leg off the ball
Increase time
Increase time
Increase time
Increase time
35 (2)
Bottom arm on hand, top arm by side 35 (2) Increase time 35 (2) Top arm in air
Z each side.
data was analyzed and it determined that data was parametric. Therefore, A 2 2 (static, dynamic test time) multivariate analysis of variance (MANOVA) with repeated measures was performed to determine the effect of training
Table 2
Dynamic core stability program. Exercise, frequency, duration and applied progression and overload for each week.
Exercise
Jack knife
Russian twista
Reverse hyperextension
Lateral rolla
Hip crossovera
Reverse crunch
8 (2) Hands together, wide feet 10 (2) Increase reps 10 (2) Narrow feet 12 (2) Increase reps
25 (2) Arms by side
8 (2) Wide feet
8 (2) Arms by side
20 (2) Arms on knees
35 (2) Increase reps 35 (2) Hands on chest 45 (2) Increase reps
12 (2) Increase reps 12 (2) Narrow feet 8 (2) Increase reps
30 (2) Increase reps 25 (2) Arms on chest 35 (2) Increase reps
10 (2) Add weight plate 12 (2) Increase reps
40 (2) Arms in front
10 (2) Lift 1 leg
10 (2) Increase reps 12 (2) Increase reps 8 (2) Elbows up, hands on chest 10 (2) Increase reps
45 (2) Increase reps
12 (2) Increase reps
12 (2) Increase reps
Week 1
Reps (sets) Instruction
Week 2
Reps (sets) Progression Reps (sets) Progression Reps (sets) Progression
8 (2) Hands wide, knees on ball 12 (2) Increase reps 12 (2) Hands narrow 8 (2) Toes on ball
Week 5
Reps (sets) Progression
12 (2) Increase reps
Week 6
Reps (sets) Progression
16 (2) Increase reps
Week 3 Week 4
a
on each parameter measured. Independent variables were gender, age and training type. Mauchly’s test of sphericity revealed that my data remained normally distributed across all time points (P > 0.05). Where a main effect was observed,
Z each side.
30 (2) Hands by temples 40 (2) Increase reps
Influence of dynamic versus static core exercises on performance in field based fitness tests a least significant difference (LSD) post hoc analysis was conducted to identify the source of the difference (P < 0.05). Further analysis of the data was carried out using Pearson’s correlation coefficient which identified inter-relationships between all test variables. All statistical analysis was carried out using SPSS for windows version 14. Intra-subject reliability was based on the vertical jump scores with an intraclass correlation coefficient of 0.95 obtained.
Results Static/dynamic core and field based tests Table 3 presents the results of each core and field based test for both training groups before and after 6 weeks of training. The mean scores of the dynamic core training group were improved at the post-test in six out of the seven functional tests; however the mean scores of the static core training group only showed improvement in five out of seven tests. Both groups improved in all core based tests (Static Group e Plank: F (1 10) Z 11.755, P Z 0.000; Double leg lowering: F (1 10) Z 1.04, P Z 0.000; Back Extension: F (1 10) Z 97.5, P Z 0.006; Dynamic Group e Plank: F (1 10) Z 81.8, P Z 0.000; Double leg lowering: F (1 10) Z 40.1, P Z 0.000; Back Extension: F (1 10) Z 16.64, P Z 0.002). Post Hoc LSD found the
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dynamic training group to show greater improvements than the static group in all 3 core tests (P < 0.05). No improvements were found in any of the dynamic tests for both static and dynamic groups (P > 0.05). However, standing stork scores increased in the static group post training (F1 10 Z 1.16, P Z 0.000) (Fig. 1). For the static training group, Pearson’s Correlation coefficient found strong positive relationships between the plank/double leg lowering test (0.817), plank/vertical jump height (0.821), and standing stork/double leg lowering test (0.820). Very strong negative relationships were found for the plank/20 m sprint test (0.927), and double leg lowering/20m sprint test (0.822). The dynamic training group was found to have strong positive relationships between the plank/20 m sprint test (0.942), and moderately strong positive relationships between medicine ball throw/back extensions (0.805) and between 20 m sprint/ vertical jump height (0.794).
Discussion The purpose of the study was to compare the effects of a 6 week core stability training program with exercises performed on an unstable surface on field based performance tests. This study suggests that 6 weeks of both static and
Table 3 Static and dynamic core and field based test results after 6 weeks of training for both static and dynamic training groups (means SD). Static indicates the group that performed a static core training program; Dynamic indicates that the group performed a dynamic core training program. n Static core tests Plank (sec) Static 6 Dynamic 6 Double leg lowering (sec) Static 6 Dynamic 6 Dynamic core tests Back extension (reps) Static 6 Dynamic 6 Static field based tests Standing stork (sec) Static 6 Dynamic 6 Dynamic field based tests Vertical jump (cm) Dynamic 6 Static 6 20 m Sprint (sec) Static 6 Dynamic 6 Medicine ball throw (m) Static 6 Dynamic 6 NS Z P > 0.05. * Z P < 0.01. * Z P < 0.001.
Pre
Post
% Difference
p
59.0 4.69 51.76 4.43
64.0 4.6 63.8 5.04
8.5% 23.3%
** **
25.65 2.62 24.68 2.45
28.18 3.78 35.43 2.58
9.9% 43.6%
** **
67.00 4.34 65.60 2.16
77.80 2.64 70.10 1.94
14.9% 45.8%
* *
3.98 0.17 4.42 0.43
6.55 0.44 4.80 0.48
64.5% 8.6%
** NS
33.4 1.92 32.9 1.36
32.7 2.16 34.7 1.75
0.9% 6.1%
NS NS
5.56 0.48 5.51 0.31
5.50 0.30 5.59 0.41
1.1% 1.4%
NS NS
3.48 0.36 3.53 0.22
3.58 0.26 3.5 0.22
2.9% 0.8%
NS NS
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Figure 1 Mean pre- and post training standing stork scores for both groups (N Z 12).
dynamic type core training improves core performance (P < 0.05). However, no transfer of training effect to the dynamic tests was shown (P > 0.05). This is the first empirical study to examine the effect of static versus dynamic core stability ball training on physical performance. While core stability ball training remains a popular adjunct to training for many athletes and anecdotal evidence supports its widespread use, results of this study appear to be consistent with previous research which has found no transfer of training effect (Nesser et al., 2008; Scibek et al., 2001; Tse et al., 2005). The static training group had a significant transfer into the balance test, which accepts part of our hypothesis and is similar to previous research. Rutherford and Jones (Rutherford and Jones, 1986) found that early adaptations in short term static core training resulted in greater gains in torso balance. Supporters of instability training propose the neuromuscular system is challenged to a greater extent and increases proprioceptive demands (Rutherford and Jones, 1986). The unstable nature of the ball forces one to make postural adjustments to increase co-ordination, which require activation of the appropriate core musculature to stabilize the lumbar spine. The deep postural muscles of the trunk have a primary purpose to ensure this lumbar stabilization and to maintain the body’s centre of gravity within its base of support to minimize loss of balance (Anderson and Behm, 2005). However, although static core training has proved effective in a measure of static balance, more sports specific research may be needed to clarify this transfer. No improvements were found in the overhead medicine ball throw, 20 m sprint and vertical jump height scores post both static and dynamic training. These results provide no support for the proposal of a more enhanced and efficient transfer of energy due to an enhanced core. Therefore we reject part of our hypothesis in that dynamic exercise will demonstrate a positive transfer of training effect to dynamic tasks. This is in agreement with Scibek and colleagues (Scibek et al., 2001) who looked at the effect of Swiss ball core stability training on subsequent swim performance. Their results showed enhanced core strength in static exercises
K.L. Parkhouse, N. Ball however no improvements in swim performance. Furthermore Nesser and colleagues (Nesser et al., 2008) showed no correlation of core strength to strength and power measures in collegiate athletes. This indicates that power performance may not be affected by core strength refuting previous claims. However core training has been shown to improve 5,000 m run times (Sato and Mokha, 2009) indicating that core training modalities may have a better transfer to more endurance based events in the resistance of fatigue and maintenance of posture (Brumitt, 2004). Stanton and colleagues (Stanton et al., 2004) showed no improvement in running economy, however did not include a timed measure for the run trials performed. These studies and the current study’s findings support the notion that core training emphasizes local muscle adaptation and core strength without concomitant improvements in power based physical performance. Although the outcomes appear clear, it must be highlighted that only 12 participants were used in the study. We suggest that any future studies in this area should include a much larger sample size to ensure sound reliability of results. Furthermore, the transfer of training effect of the dynamic core exercises to the dynamic movements may have required a longer duration training program or an increased frequency of sessions. Early phase adaptations including increased stability, neuromuscular activity and proprioceptor activity have been shown after 5 weeks of training doing abdominal and one lower back exercise per day (Cosio-Lima et al., 2003), however these improvements were shown mainly in neuromuscular changes opposed to strength changes as measured by isokinetic testing. Thus the neuromuscular control and co-ordination trained by core dynamic exercises may only improve muscular recruitment in the initial phases opposed to the transferring into an external measure. Thus the benefits of the core training program here for the dynamic exercise may not be transfer into performance measures but may potentially improve kinematic and kinetic measures. Alongside program duration the nature of the exercise used may be changed for athletes with free weight exercises using moderate levels of instability may be more suitable to maintain specificity (Behm et al., 2010). The concept of specificity suggests that quick, explosive dynamic performance variables are likely to be improved by similar type training actions. To train improved speed of force application more importance is placed on performing the exercise powerfully compared to the selection of the exercise movement (Behm and Sale, 1993). Although dynamic exercises were performed by the dynamic training group, explosive power and high rates of force development were not emphasized and subsequently not transferred over. A lower repetition range with emphasis on increased speed of movement whilst maintaining lumbo-pelvic stability may have seen a better transfer into the sprint, jump and throw tests as the core would be trained in a similar manner to its use within these tests. The loading measures used in this study may not have been sufficient to improve core muscle function during dynamic exercises. Hibbs and colleagues (Hibbs et al., 2008) suggested that the cores are trained more for everyday requirements (low loads, slow movements) opposed to an athlete requirement of high load and resistive movements. The population group in this study
Influence of dynamic versus static core exercises on performance in field based fitness tests indicated a better use of their core strength in static movements compared to the high force dynamic field tests. In summary, the results of this study suggest that 6 weeks of stability ball training doesn’t improve dynamic field based performance tests based on the sample size used. The benefits of core training may reside in long term athlete development programmes whereby appropriate posture and core strength may transfer into improved co-ordination and exercise performance. Increases in training duration and speed of movement in dynamic core exercises may provide a more specific stimulus of the core for transfer into dynamic field based movements, however this warrants further investigation.
Practical applications The current study shows that both static and dynamic core stability exercises trained over a 6-week period are able to effectively increase the core strength of participants. These strength benefits do not transfer into improved dynamic performance in sprinting, throwing and jumping. The study indicates that short term training may only improve core strength by reducing fatigue in the core musculature and allowing the athlete more neuromuscular control during balance. A program that incorporates both static and dynamic exercises may provide these benefits if the dynamic exercises are then performed with increased velocity. This may improve the transfer of training effect into dynamic performance. It must be understood that the findings may only be applicable to the population under investigation and the effects on elite athletes is unknown. However due to the assumed improved core strength and physicality of elite performers it can be assumed that their scope for adaptation is smaller than the current population and thus non-significant finding for core transfer into dynamic performance can be reasonably assumed. Findings do not discourage the use of core stability ball training; instead, they suggest that specificity on the rate of force development, speed and power of each core exercise may be needed to transfer into sporting performance.
Acknowledgements Sincere thanks to all the participants who devoted their time and effort to this study.
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Beache, T.R., Earle, R.W., 2000. Essentials of Strength Training and Conditioning. Human Kinetics, Champaign, IL. Boyle, M., 2004. Functional Training for Sports. Human Kinetics, Champaign, IL. Brown, T.D., 2006. Getting to the core of the matter. Strength and Conditioning Journal 28, 50e53. Brumitt, J., 2004. The missing component to core training: endurance. NSCA Performance Training Journal 3, 233e239. Carter, J.M., Beam, W.C., McMahan, S.G., Barr, M.L., Brown, L.E., 2006. The effects of stability ball training on spinal stability in sedentary individuals. Journal of Strength and Conditioning Research 20, 429e435. Chek, P., 1999. Swiss ball exercises for swimming, soccer & basketball. Sports Coach 21, 12e13. Cissik, J.M., 2002. Programming abdominal training, part 1. Strength and Conditioning Journal 24 (1), 9e15. Cosio-Lima, L.M., Reynolds, K.L., Winter, C., Paolone, V., Jones, M.T., 2003. Effects of physioball and conventional floor exercises on early phase adaptations in back and abdominal core stability and balance in women. Journal of Strength and Conditioning Research 17, 721e725. Gamble, P., 2007. An integrated approach to training core stability. Strength and Conditioning Journal 29, 58e68. Goodman, P.J., 2003. The core of the workout should be on the ball. NSCA Performance Training Journal 2, 34e38. Haff, G.G., Carlock, J.M., Hartman, M.J., Kilgore, J.L., Kawamori, N., Jackson, J.R., Morris, R.T., Sands, W.T., Stone, M.H., 2005. Forcetime curve characteristics of dynamic and isometric muscle actions of elite women olympic weightlifters. Journal of Strength and Conditioning Research 19, 741e748. Harris, N.K., Cronin, J., Taylor, K., Jidovtseff, B., Sheppard, J., 2010. Understanding position transducer technology for strength and conditioning practioners. Journal of Strength and Conditioning Research 32 (4), 66e79. Hedrick, A., 2000. Training the trunk for improved athletic performance. Strength and Conditioning Journal 22, 50e61. Hibbs, A.E., Thompson, K.G., French, D., Wrigley, A., Spears, I., 2008. Optimizing performance by improving core stability and core strength. Sports Medicine 38, 995e1008. Jeffreys, I., 2002. Developing a progressive core stability program. Strength and Conditioning Journal 24, 65e66. Johnson, P., 2002. Training the trunk in the athlete. Strength and Conditioning Journal 24, 52e59. Kibler, W.B., Press, J., Sciascia, A., 2006. The role of core stability in athletic function. Sports Medicine 36, 189e198. Knudson, D., 2001. The validity of recent curl-up tests in young adults. Journal of Strength and Conditioning Research 15, 81e85. Lehman, G.L., Gordon, T., Langley, J., Pemrose, P., Tregaskis, S., 2005. Replacing a Swiss ball for an exercise bench causes variable changes in trunk muscle activity during upper limb strength exercises. Dynamic Medicine 4. doi:10.1186/1476-5918-4-6. Marshall, P.W., Murphy, B.A., 2005. Core stability exercises on and off a Swiss ball. Archives of Physical Medicine and Rehabilitation 86, 242e249. doi:10.1016/japmr.2004.05.004. McCurdy, K.W., Langford, G.A., Doscher, M.W., Wiley, L.P., Mallard, K.G., 2005. The effects of short-term unilateral and bilateral lower-body resistance training on measures of strength and power. Journal of Strength and Conditioning Research 19, 9e15. McGill, S.M., 2001. Low back stability: from formal description to issues for performance and rehabilitation. Exercise and Sport Science Reviews 29, 26e31. Murphy, A.J., Wilson, G.J., 1996. Poor correlations between isometric tests and dynamic performance: relationship to muscle activation. European Journal of Applied Physiology and Occupational Physiology 73, 353e357. doi:10.1007/BF.0242.5498. Nesser, T.W., Huxel, K.C., Tincher, J.L., Okada, T., 2008. The relationship between core stability and performance in division
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Journal of Bodywork & Movement Therapies (2011) 15, 525e527
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PREVENTION & REHABILITATION: EDITORIAL
Stimulus and response
Primal Lifestyle, Unit 5 Glebelands, Vincent Lane, Dorking, Surrey RH4 3HW, UK The very origins of life on Earth were based on a stimuluseresponse; a photoreceptive pigment responding to the stimulus of the sunlight. From this the most basic of hormonal systems evolved, and from around 3.5 billion years ago, an electrochemical dance was the key controlling influence on the behavior of organisms. It wasn’t for, nigh-on, a further 3 billion years (around 490 million years ago) that organisms had evolved to the extent that a nervous system had formed along the axis of the organism’s body to allow for a higher-speed stimuluseresponse system (Raff, 1996). It is of little surprise, then, that at this current juncture of evolution, the ability of the human organism to respond to the stimuli applied to it is both deeply complex and intricately wired so as to have plethoric interwoven and back-up systems. However, this doesn’t stop such systems from sometimes crashing, nor does it necessarily inform our methods of rehabilitating crashes. It is this author’s belief that understanding the way the system is wired should provide deep insights into how to effectively re-wire it, when such crashes do occur. In this Rehabilitation & Prevention section there are two very similar, yet very disparate papers featured. The first is a paper, which is more of a classic manual therapy-style review paper looking at the evidence behind reported successes of various interventions: Movement therapy induced neural reorganization and motor recovery in stroke: A review (Arya et al., 2011). The second paper is a brief case study of a patient with chronic migraine who is treated using the Vojta and DNS approaches which have evolved from the same centre in Prague that gifted the world of manual therapy with Vladimir Janda and Karel Lewit, among others: A case study utilizing Vojta/Dynamic Neuromuscular Stabilization
E-mail address:
[email protected].
therapy to control symptoms of a chronic migraine sufferer (Juehring and Barbara, 2011). To better understand what these papers offer, a brief description of three useful clinical models is presented below.
Modeling & human health According to Holland (2000) “A well conceived model can yield organized complexities that repay decades and centuries of study. If the [model] is faithful, we can make predictions into the indefinite future” In this editorial, there are 3 models shared with the reader to help to contextualize the research papers. The first is Panjabi’s famous model of joint stability. The second is a schema for motor learning described by Lederman. The last is the author’s own evolutionary model designed to provide a hierarchical understanding of ascending and descending influences on human health.
Motor control In 1992, Panjabi proposed the model of joint stability in which he described the 3 key components for optimal motor control about the joint. These comprised the passive, the active and the neural components of the joint. Disruption to any of these components would compromise the overall function of the joint (Figure 1). How this may be applied to the papers featured in this section is that, far from just activating the muscles in nonspecific electrochemical ways, the effective retraining of muscle activation must surely depend on dynamic interplay of information coming in to the nervous system from higher centers and from the passive (connective) and active (muscular) tissues.
1360-8592/$ - see front matter ª 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2011.07.001
PREVENTION & REHABILITATION e EDITOR: MATT WALLDEN
Matt Wallden, MSc Ost Med, BSc (Hons) Ost Med, DO, ND
PREVENTION & REHABILITATION e EDITOR: MATT WALLDEN
526
Figure 1 Panjabi et al.’s (1989) model of joint stability predicts that for optimal joint function each of the 3 components must be fully functional. If the nervous system is aberrant (inhibited, facilitated or dyssynergic), motor recruitment cannot be optimal and will result in stress on the passive system. The passive system is the primary component of feedback for the neural system (including joint proprioception, mechanoreception and even spindle cell feedback from tendons), so any dysfunction at the passive level (inflammation, neovascularisation, creep or contracture) will disrupt optimal afferent information processing. The efferent drive to the active system, controlled by the neural subsystem, will only be as effective as the afferent drive coming into the neural system.
Manual treatment of muscles may have useful physiological effects that enhance their ability to respond to subsequent or accompanying rehabilitation protocols, however, when applied in isolation, repatterning of motor habits is improbable, so the likelihood of long-term benefits are questionable. Indeed this is what is found in the Arya et al’s. (2011) paper and what is implied by the Juehring and Barbara’s (2011) paper.
Motor learning In 1997, Lederman described a motor learning model in which he explained that in order for there to be habitual changes in a patient’s motor behavior, active engagement of the patient is required; over and above simple passive approaches (such as massage, stretching, mobilization or manipulation) (Figure 2). How this model relates to the papers included in this section is that the Arya et al’s. (2011) paper demonstrates that passive modalities are now rarely used and/or require more research to demonstrate efficacy; while the active approaches, which engage central processes are enjoying greater clinical success, as the model predicts. The Juehring and Barbara’ (2011) case study demonstrates that, while the more passive Vojta’ approach may facilitate deeply embedded neural programs, the DNS approach adds a further active component to the therapeutic intervention; which is, likely, key to the favorable outcome, as predicted by Lederman’s model.
Dimensional mastery Lastly, in 2008, Wallden proposed a model of dimensional mastery (Wallden, 2008, 2010) in which it is suggested that
M. Wallden
Figure 2 Lederman’s schema of motor learning predicts that passive modalities applied to the patient, will only have a temporary effect based on their influence being modulated primarily subcortically (at the segmental/peripheral reflexive level). In contrast, skilled active modalities applied by the patient must, by their nature, be centrally processed and therefore influence motor habits, creating more permanent changes in motor behaviour.
the evolution of morphophysiology provides insight into the foundations of human function and therefore the processes through which human function can be restored. How this model relates to the papers in this section is that it implicates breathing and eating as fundamental underpinning to health, the former of which is an integral part of the Vojta/DNS approach. It also suggests that dimensional mastery (mastery of each of the dimensions of space) follows a specific sequence, which just so happens to be the sequence of mastery seen in the evolution of species and in infant motor development; something also described in the Vojta/DNS approach (Juehring and Barbara, 2011), but found to be missing in the Stroke rehabilitation approaches described (Arya et al., 2011). It is also apparent that when isolationbased approaches are utilized their success is limited, such as the bodyweight supported treadmill training, described by Arya et al. (2011). From a dimensional mastery point of view, this would figuratively be learning to run before you can walk, or more literally, learning to walk before you can crawl, creep, twist, turn or breathe functionally. Finally, as you follow the natural progression of the dimensional mastery model (Figure 3) where the 3 dimensions of space become mastered, the next progression is to consider both the 4th and the 5th dimensions. The 4th is the dimension of time and mind, while the 5th is the dimension outside of spaceetime where, traditionally, spirituality, non-locality, and the timeless dwells. In the context of the two papers presented, the Stroke paper demonstrates that the use of mind from a practitioner perspective to deduce complex, often expensive, approaches to rehabilitation may sometimes yield poor results; if mastery of the foundation spatial dimensions is not first mastered. Both papers demonstrate that repetition is required to learn new e or to re-learn old e skills (as described by Lederman, 1997) and that repetition can, of course, only occur across the 4th dimension of time.
Editorial
527 The stroke paper also highlights that, from a patient’s perspective, if the mind (4th dimensional) focus is specific enough, it may be of benefit to the patients recovery, in the form of mental imagery. However, both papers highlight the requirement for the patient’s engagement, their interaction, their embracing of their rehabilitation program; and it is this prerequisite e their belief in the process, that is perhaps most key.
Conclusion
References Holland, J., 2000. Emergence. OUP, Oxford. Lederman, E., 1997. Fundamentals of Manual Therapy. Churchill Livingstone, Edinburgh, pp. 105. Panjabi, M., Abumi, K., Duanceau, J., Oxland, T., 1989. Spinal stability and intersegmental muscle forces. A biomechanical model. Spine 14 (2), 194e200. Raff, R., 1996. The Shape of Life e Genes, Development, and the Evolution of Animal Forms. University of Chicago Press, Chicago. Wallden, M., 2008. In: Chaitow, L. (Ed.), Rehabilitation & Movement Re-education Approaches in Naturopathic Physical Medicine. Wallden, M., Nov 2010. Phylontogenic factors in motor control: an organismal model of systems integration in motor control. In: 7th Interdisciplinary World Congress on Low Back and Pelvic Pain. Los Angeles; pp. 542e544.
PREVENTION & REHABILITATION e EDITOR: MATT WALLDEN
Figure 3 Wallden’s model of dimensional mastery recognizes how development of increasing neurological complexity across time correlates with the greater computational power required to master the 4 dimensions of spaceetime reality. The model predicts that if a foundational level of mastery is impaired or forgotten, mastery of each successive dimension will be incomplete or unstable. Clinically, it predicts nutritional and respiratory function underpins movement function, and that movement function will most effectively be built through mastery of peristaltic (radial) contraction, followed by frontal (lateral), followed by sagittal (front-back), and concluded by transverse plane (rotational) motions. The neurological complexity required to master such movement patterns is a system that has the neural capacity to create mind (and to conceptualize time). The transcendence of mind and time, moving outside of the space-time continuum, is considered the 5th dimension; often referred to as the spiritual realm.
The message is, if the foundations are in place, the program is intelligently designed to invoke the correct stimuli across time, and the patient has no doubt in their mind, and therefore truly believes in the process, then the response is likely to be most optimal.
Journal of Bodywork & Movement Therapies (2011) 15, 528e537
available at www.sciencedirect.com
journal homepage: www.elsevier.com/jbmt
REHABILITATION
Movement therapy induced neural reorganization and motor recovery in stroke: A review
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Kamal Narayan Arya, MOT, PhD Scholar (Neurology), Sr. Occupational Therapist a,b,*, Shanta Pandian, MOT (Neurology), Superintendent OT (OPD) b, Rajesh Verma, DM (Neurology), DNB (Neurology), Professor a, R.K. Garg, DM (Neurology), Professor & HOD a a
Department of Neurology, CSM Medical University (KGMU), Lucknow, UP 226003, India Pt. Deendayal Upadhyaya Institute for the Physically Handicapped, University of Delhi, Ministry of Social Justice & Empowerment, Govt. of India, New Delhi 110002, India
b
Received 7 October 2010; received in revised form 22 January 2011; accepted 29 January 2011
KEYWORDS Stroke; Neurorehabilitation; Cortical reorganization; Neuroplasticity
Summary This paper is a review conducted to provide an overview of accumulated evidence on contemporary rehabilitation methods for stroke survivors. Loss of functional movement is a common consequence of stroke for which a wide range of interventions has been developed. Traditional therapeutic approaches have shown limited results for motor deficits as well as lack evidence for their effectiveness. Stroke rehabilitation is now based on the evidence of neuroplasticity, which is responsible for recovery following stroke. The neuroplastic changes in the structure and function of relevant brain areas are induced primarily by specific rehabilitation methods. The therapeutic method which induces neuroplastic changes, leads to greater motor and functional recovery than traditional methods. Further, the recovery is permanent in nature. During the last decade various novel stroke rehabilitative methods for motor recovery have been developed. This review focuses on the methods that have evidence of associated cortical level reorganization, namely task-specific training, constraint-induced movement therapy, robotic training, mental imaging, and virtual training. All of these methods utilize principles of motor learning. The findings from this review demonstrated convincing evidence both at the neural and functional level in response to such therapies. The main aim of the review was to determine the evidence for these methods and their application into clinical practice. ª 2011 Elsevier Ltd. All rights reserved.
* Corresponding author. Department of Neurology, CSM Medical University (KGMU), Lucknow, UP 226003, India. E-mail address:
[email protected] (K.N. Arya). 1360-8592/$ - see front matter ª 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2011.01.023
Introduction Stroke is the second leading cause of death and one of the leading causes of adult disability in the world today (Gresham et al., 1997). Traditionally, stroke rehabilitation comprised a number of neurophysiological approaches developed by Bobath, Rood, Kabat, Brunstrom and Carr & Shepherd (Paci, 2003; Chan et al., 2006). It also includes compensation of lost movement through the use of the unaffected arm or leg (Dobkin, 2004). Some of the neurophysiological approaches, such as Bobath, are based on theories of motor control and motor learning. Due to frequent changes and development of these theories such approaches need to be redefined. For example, traditionally Bobath approach was based on reflexive and hierarchical theory of motor control while now it is based on the theory of distributed control of the central nervous system (Shumway-Cook and Woollacott, 2006). Though stroke is a leading cause of disability, there is no accepted rehabilitation method (Jette et al., 2005). Most of the traditional approaches used for enhancing recovery in post stroke patients, do not have strong evidence (Paci, 2003; Hafsteinsdo ´ttir et al., 2005). Therapists use eclectic approaches to intervention rather than one specific intervention technique (Schaechter, 2004). During the past two decades, compelling evidence in neuroscience has resulted in knowledge that the brain can change or reorganize itself in response to sensory input, experience and learning (Chan et al., 2006). This ability of the brain and other parts of the central nervous system to reorganize itself is referred to as Neuroplasticity (Rossini et al., 2003) and exclusively of cortex as Cortical plasticity (Jain, 2002). Neuroplasticity occurs in both a healthy and injured brain (Hubbard et al., 2009). For example, the structural brain changes have been reported among the healthy cab drivers due to a purposive activity, such as the frequent use of a street and traffic pattern (Gauthier et al., 2008). Neuroimaging findings in animals (Markus et al., 2005) and humans (Richards et al., 2008b) support the basis of reorganization in many parts of the brain both in response to recovery and goaldirected motor therapy (Turkstra et al., 2003; Dobkin, 2004; Nudo, 2007). Richards et al. (2008b) conducted a meta-analysis of 13 studies to examine changes associated with neural plasticity in post stroke patients following movement based therapy. The changes were examined either by transcranial magnetic stimulation, functional magnetic resonance imaging (fMRI), or positron emission tomography (PET). Results indicated that neural changes in the sensorimotor cortex of the lesioned hemisphere accompany the motor gains in the paretic upper extremity. The traditional neurorehabilitation approaches for post stroke patients focus on motor and functional recovery (Chan et al., 2006). Motor recovery refers to an ability of an individual to carry out movements under voluntary control in the same manner as before the stroke (Levin et al., 2009), while functional recovery refers to improvement in the ability of the individual to perform activities such as selfcare and mobility independently (Davis, 2006). Post stroke, recovery also occurs at brain level (neurological recovery), which is generally associated with the structural and
529 functional reorganization of brain. Both motor and functional recoveries are influenced by neurological recovery. However, functional recovery may also occur independently of neurological recovery (Teasell et al., 2005). Research in neuroplasticity has led to the development of new movement therapy methods inducing neural as well as motor recovery. Many movement therapy protocols such as taskspecific training, constraint-induced movement therapy (CIMT), and mental imagery have preliminary but convincing evidence for their impact on such reorganization and associated motor and functional recovery (Wolf et al., 2006; Page et al., 2007, 2009; Gauthier et al., 2008; Richards et al., 2008a, b). Thus, neural reorganization after stroke is thought to be an important mechanism to facilitate motor recovery (Jones et al., 2009). Furthermore, most of these protocols utilize the principles of motor learning (Krakauer, 2006). Motor learning refers to the permanent changes in behavior because of practice or experience (Schmidt, 2005). The protocols target deficits in the neuromuscular system and use practice or an experience for a specific goal or task to produce skilled motor action (Jette et al., 2005). For example, doing repetitive practice for reaching a glass of water to improve the elbow extension. Learning such motor skills cause structural and functional changes in the motor cortex and cerebellum. Further, the changes are indicative of motor recovery, which is permanent in nature (Kleim and Jones, 2008). Such changes are not found with simple exercises, for example, performing elbow flexioneextension without any goal (Nudo et al., 2001; Maldonado et al., 2008). Hence, the concept of neuroplasticity is important in stroke rehabilitation. The validity of therapy induced neuroplasticity has also been strongly supported by activation of specific brain areas in many fMRI studies. These studies have shown the diversity and complexity of reorganization patterns (Richards et al., 2008b). The process of reorganization is dynamic and also depends upon various factors such as the time period elapsed between stroke and therapy, and the intensity and type of therapy given (Nudo et al., 2001; Nudo, 2003). The aim of the review was to identify the evidence for neuroplasticity as well as associated motor and functional recovery in response to various movement based therapeutic methods and to determine the application of these methods in stroke rehabilitation.
Search strategy Though the review was not systematic, the following search strategy was used to review current evidence from the literature: Search engines: Pubmed, the Cochrane Library of systematic reviews Keywords used Stroke and Rehabilitation Motor learning Motor control Motor recovery
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K.N. Arya et al. Neuroplasticity Cortical organization
Inclusion criteria Types of participant: stroke survivors in the acute phase, the rehabilitation phase and the chronic phase. Type of event: ischemic and hemorrhagic stroke Types of outcome measure: outcomes of interventions focused on neurological recovery (brain reorganization),/motor recovery (motor performance)/functional recovery (activities of daily living). Research design: meta-analysis, systematic reviews, reviews and randomized controlled trials which incorporated methods to investigate the neural reorganization. Time of publication: articles published in English between January 2000 and December 2009.
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Motor learning Most of the evolving movement therapies which induce cortical reorganization are based on the principles of motor learning. Motor learning leads to sprouting of dendrites, formation of new synapses, alteration in existing synapses and production of neurochemicals (Mulder and Hochstenbach, 2001). These changes are greater if the practice method is meaningful, repetitive and intensive in nature (Daly and Ruff, 2007). Further, such practice method leads to long-term retention and generalization of the learned motor behavior. For example, if an individual tries to reach for a glass filled with water to attempt to drink (meaningful), 50 times (repetitive), thrice daily for four weeks (intensive). Motor improvement then achieved such as an increased range of elbow extension would be permanent in nature and could be applied in other task performances (Kleim and Jones, 2008; Hubbard et al., 2009). Thus, stroke rehabilitation methods should consist of intensive and repetitive practice of meaningful tasks. Recovery achieved by motor learning may be divided into true or compensatory motor recovery. True motor recovery happens when undamaged or alternative pathways transport commands to the same muscles that were used before the injury (Krakauer, 2006). A proposed mechanism for this is through redundancy of motor cortical areas with unmasking of pre-existing corticocortical connections (Teasell et al., 2005). Compensation is the use of alternative muscles to accomplish the task goal (Krakauer, 2006). Motor learning is required for both the types of recovery (Krakauer, 2006). However, the goal of all the emerging movement based therapeutic methods for post stroke rehabilitation is true motor recovery. Most of these methods are based on motor learning and have meaningful, repetitive and intensive practice as a key element for training (Krakauer, 2006; Kleim and Jones, 2008; Richards et al., 2008a).
Task-specific training Task-specific training is a term that has evolved from the movement science and motor skill learning literature (Schmidt, 2005). Other terms interchangeably used are ‘repetitive task practice’, ‘repetitive functional task practice’, and ‘task-oriented therapy’ (French et al., 2007;
Hubbard et al., 2009). Task-specific training emphasizes the practice and repetition of skilled motor performance to improve individual’s functional abilities (Bayona et al., 2005). Task-specific training may restore function by using spared parts of the brain, which are generally adjacent to the lesion and/or recruiting supplementary parts of the brain (Nudo et al., 2000). There is increasing evidence of neural plastic changes associated with such training (Jang et al., 2003; Luft et al., 2004; Richards et al., 2008a, b). Task-specific training, in comparison to traditional stroke rehabilitation, induces long-lasting motor learning and associated cortical reorganization specific to the corresponding areas being used (Bayona et al., 2005; Dobkin, 2005; Schmidt, 2005; Gauthier et al., 2008; Harvey, 2009). In response to task-specific training, Jang et al. (2003) found cortical activation changes with the upper extremity functional recovery. fMRI changes showed decrease activation in the unaffected and an increase in the affected primary sensorimotor cortex. Similarly, Luft et al. (2004), observed increased activation in the contralesional cerebrum and ipsilesional cerebellum (p Z 0.009), in response to repetitive bilateral arm training as compared to control therapy. Furthermore, repetitive task-specific training has been found to achieve better functional gains when compared to non-repetitive training (Langhammer and Stanghelle, 2000; Salbach et al., 2004; Michaelsen et al., 2006; Page et al., 2007). It has also been found to be effective in gait retraining, sit-to-stand retraining and motor training of the upper limb (Hubbard et al., 2009). Langhammer and Stanghelle (2000), in an RCT of 61 stroke patients, compared the motor relearning programme (MRP), consisting of physiotherapy with task-oriented strategies, and the Bobath techniques, which involve physiotherapy with facilitation/inhibition strategies. Although statistically insignificant, patients who were treated with the taskoriented strategies were more likely to improve on tests of motor function but not on more general functional outcome testing. A double-blind randomized control trial was also conducted to determine whether task-specific training with trunk-restraint (TR) produces greater improvements in arm impairment and function than training without TR in 30 patients with chronic hemiparesis (Michaelsen et al., 2006). TR group exhibited greater improvements in impairment and function as compared to control (p < 0.05). There was increased active elbow joint range in TR group while increased compensatory movement in the control group. Salbach et al. (2004) evaluated the efficacy of a task-orientated intervention in enhancing competence in walking in 91 chronic stroke patients. Significant between-group effects of 0.21 m/s (95% CI: 0.12, 0.30) and of 0.11 m/s (95% CI: 0.03, 0.19) in maximum and comfortable walking speed, respectively, were observed. People with a mild, moderate or severe walking deficit at baseline improved an average of 36, 55 and 18 m, respectively; in 6-min walk test performance following the experimental intervention. In a systematic review, French et al. (2007) summarized the evidence of task-specific training in post stroke patients. Overall, it was found that some form of task-specific training resulted in improvement in global motor function, and in both arm and lower limb function, although the evidence for upper limb interventions was less clear because of insufficient good-quality evidence.
In addition to task specificity, environment for the training is important in motor learning and associated cortical reorganization (Do ¨bro ¨ssy and Dunnet, 2001). Environmental factors play an important role in inducing the optimum response from the individual during task-specific training (Davis, 2006). The therapeutic environment which provides a greater opportunity for activity and interaction is termed as an enriched environment (Do ¨bro ¨ssy and Dunnett, 2001). The enriched environment provides individuals with clear understanding of what is being expected of them during task-specific practice and improves their performance (Davis, 2006). For instance, animals exposed to complex housing environments post injury typically have improved the functional outcomes compared to animals in standard housing (Will et al., 2004). Similarly, an individual would stand for a longer period of time if he is brushing his teeth in front of a washbasin as compared to someone who simply stands in the middle of a therapy room. Thus, stroke rehabilitation programs should include repetitive task-specific movement training in an enriched environment in order to promote cortical reorganization, motor and functional recovery.
Constraint-induced movement therapy (CIMT) CIMT has received greatest attention among all the emerging movement based therapeutic methods in the last decade. It has shown significant improvement of the paretic upper limb function in chronic stroke patients (Schaechter, 2004). It is one of the most studied motor rehabilitation protocols for post stroke patients. CIMT combines various interventional principles aimed at enhancing the use of the paretic upper extremity after stroke. CIMT was developed originally to ameliorate the phenomenon of “learned non-use” in which individuals with stroke form the habit of not using their paretic upper extremity despite the ability to use it in some functional activities. It mainly consists of constraining the less affected arm by wearing a sling or mitt during waking hours and practicing tasks with the more affected one (Taub et al., 2006). In addition to repetitive practice of a task, it also includes successive approximation. The successive approximation is a process of either increasing the successful numbers of repetitions or reducing the time to complete the task successfully with one effort (Wolf, 2007). fMRI studies on the adult stroke patients have demonstrated functional changes at the physiological level of brain, including changes in cortical excitability, metabolic rate, and blood flow after CIMT (Schaechter et al., 2002). Although important, these alterations in the brain physiology fluctuate rapidly over time and give findings, which may not be reliable. Structural neuroplasticity (i.e., increases or decreases in the amount of gray matter) has also been studied. Post CIMT profuse increases in the gray matter has been found in the sensory and motor cortical areas, both contralateral and ipsilateral to the affected arm. The structural changes were accompanied by large improvements in spontaneous realworld arm function (Gauthier et al., 2008). Hence, CIMT has evidence for the physiological and structural brain changes as well as improvement in the affected upper limb function in post stroke patients. Various trials have been conducted to examine the effectiveness of CIMT in improving motor and functional
531 recovery in post stroke patients (Hakkennes and Keating, 2005; Taub et al., 2006; Wolf et al., 2006; Lin et al., 2009). Taub et al. (2006), in their trial with 41 subjects, found large to very large improvements in the functional use of the more affected arm in the daily lives of the subjects (p < 0.0001). The changes persisted over two years. Wolf et al. (2006) conducted similar but a larger multi-site randomized clinical trial, the extremity constraint-induced therapy evaluation (EXCITE). Two hundred and twenty-two patients who had a stroke within the previous 3e9 months were recruited. CIMT produced statistically significant and clinically relevant improvements in arm motor function that persisted for at least one year. However, control group either received usual care or no treatment. The control treatment was also not matched for dose with the experimental one. These could be important confounders for the findings. Although early therapy is an important factor to induce neuroplasticity (Kleim and Jones, 2008) and CIMT is feasible in acute stage (Dromerick et al., 2000), most of the studies were conducted on chronic stroke patients. Only one CIMT trial for acute stroke patients has been found (Dromerick et al., 2009). They conducted very early constraint-induced movement during stroke rehabilitation (VECTORS), a phase II trial of CIMT with 52 acute stroke patients (within 28 days of admission). The VECTORS study did not support the hypothesis that CIMT therapy was superior to traditional therapy in acute stage of stroke. This could be due to minimal or no learned non-use during the acute phase. However, CIMT was found to be effective in a trial of small sample (n Z 14) of sub-acute stroke (mean Z 4.4-month post stroke) (Page et al., 2002). Stroke affects various health domains such as participation in the community which represents a societal perspective of functioning, for example, work and employment (Davis, 2006). Though there is evidence of CIMT intervention at various levels, participation of the client at the community level has not been studied yet. Further, almost all studies have reported its efficacy for subjects having 20 wrist extension and 10 finger extension (Hakkennes and Keating, 2005; Wolf et al., 2006; Lin et al., 2009). However, in stroke, many people (75%) do not reach this level of the hand recovery and, therefore, may not benefit from CIMT (Sawner and LaVigne, 1992; Wolf, 2007). Lin et al. (2009) studied the effect of CIMT with a little different inclusion criteria and objective. In the study, the inclusion criteria were placing the hand behind the back, moving the arm forward to a horizontal position, or performing pronation and supination with the elbow flexed at 90 (Brunnstrom stage IV), instead of specific degree of wrist and finger extension. However, again these criteria did not cover the larger proportion (>50%) of severely disabled stroke population (Sawner and LaVigne, 1992). Unlike other studies, Lin et al. used comprehensive outcome measures of motor ability, perceived functional use of the affected limb, basic and extended performance of activities of daily living, and quality of life. As compared to control group, the CIMT group exhibited significantly better performance in motor function (p < 0.06), level of functional independence (p < 0.001), extended activities during daily life (p < 0.04), and health-related quality of life after treatment (p < 0.009). In a systematic review of 14 RCTs, Hakkennes and Keating (2005) concluded that CIMT may improve upper
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532 limb function following stroke for some patients when compared to alternative or no treatment. Well-designed and adequately powered trials are further required to evaluate the efficacy of different CIMT protocols on the different types of stroke patients and to assess the impact on quality of life, cost and patient/care giver satisfaction. Given the available evidence, CIMT may be considered as one of the important movement therapies for the chronic stroke patients.
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Mental imagery/practice Mental imagery is a cognitive process of creating any experience (auditory, visual, tactile, and kinesthetic) in the mind without its actual presence (Dickstein and Deutsch, 2007). Specifically, motor imagery is an act of producing an internal representation of a movement without generating any motor output (Jackson et al., 2001; Braun et al., 2006). It is the imagination of movement/s of a body part/s, for example, imagination of the elbow flexion. Mental practice is the voluntary rehearsal of an imaginary scene, for example, imagination of eating an ice-cream using the impaired upper extremity. However, the term mental practice and motor imagery practice are used interchangeably (Dickstein et al., 2004). The concept has been taken from sport psychology, where this method is used to maintain the performance level of athletes during recovery from injury. The rationale behind this technique is the activation of same brain areas and pathways even in the absence of real movement performance. Brain mapping techniques have shown the activation of the motor cortex and other associated areas during imagery as well as during the execution of the movement (de Vries and Mulder, 2007). This capability of the cerebral cortex and related network can be exploited for stroke patients. Mental imagery can be used during the phase of recovery when volitional movements are either impossible or being performed synergistically. Studies have reported fMRI evidence of cortical reorganization induced by mental imagery. Mental practice led to increased activation of the cerebellar, premotor, primary motor cortex and striatal sensorimotor network. The changes correlated with motor and functional recovery (Lacourse et al., 2004; Page et al., 2009). It has also been suggested that mental imagery/practice alone is not enough to induce recovery. Whenever possible, it should be complemented by another evidence based motor rehabilitation approaches such as CIMT and repetitive task practice (Butler and Page, 2006; Sharma et al., 2006; Zimmermann-Schlatter et al., 2008; Page et al., 2009). In an RCT of 32 chronic stroke patients (mean Z 3.6 years) with moderate motor deficits, experimental group received 30-min mental practice (MP) sessions and physical practice while the control group received the relaxation and physical practice. Subjects receiving MP showed significant reductions in affected arm impairment and significant increases in daily arm function (both at the p < 0.0001) (Page et al., 2007). Both short term and long-term functional benefits of mental imagery on relearning and performance of daily arm function in post stroke patients have been reported in two randomized controlled trials (Liu et al., 2004; Page et al., 2007).
K.N. Arya et al. Although mental imagery was found to be effective in improving gait in post stroke clients, no randomized controlled trial has been conducted (Dickstein et al., 2004). Hence, whilst there is adequate functional, as well as neuro-imaging evidence for use of mental imaging for upper extremity rehabilitation of post stroke patients; this does not exist for the lower limb. Further, the generation of motor images is a complex cognitive skill. The skill level varies from person to person. The ability to generate strong motor images is considered to be an important determinant of the effectiveness of mental imagery. An individual may use alternative cognitive strategies that, if not screened for, could confound investigations and produce conflicting results. Few questionnaires have been developed to assess the imagery ability and accuracy (Sharma et al., 2006). Despite this, the available evidence suggests the value of mental imagery for post stroke patients. Moreover, the method is found to be highly cost effective and safe for the rehabilitation of post stroke clients. (Gaggioli et al., 2004; Page et al., 2007).
Body weight support treadmill training Ambulation is one of the most affected activities in post stroke survivors (Wevers et al., 2009). Stroke rehabilitation usually focuses on gait and gait related activities to improve mobility, although most individuals continue to have some residual disability in ambulation (Laufer et al., 2001). Initially developed for people with spinal cord injuries (Hicks and Ginis, 2008), body weight support treadmill training (BWSTT) is now also becoming a promising approach for gait rehabilitation in stroke. In this approach, body weight support, provided by a harness, reduces the biomechanical and equilibrium constraints for walking and a treadmill facilitates normal walking pattern (Laufer et al., 2001). Consequently, the individual can practice repetitive training without abnormal deviations of trunk and lower extremity. Furthermore, the training may activate spinal centers, referred to as Central pattern generators (CPGs) (Drew et al., 2008). CPGs are networks of nerve cells producing specific, rhythmic movements such as walking, without conscious effort and without the aid of peripheral afferent feedback (MacKay-Lyons, 2002). Walking is based on a “pacemaker” activity of the CPGs. CPGs generate stepping patterns consist of synergistic joint movement (Nielsen, 2003; Drew et al., 2008). For example, alternate movement of lower limbs during walking; consists of hip flexion and knee extension of one limb while hip extension and knee extension of the other limb. However, the evidence of pattern generation in humans is limited and indirect, based either on animal studies or studies of a single human subject with spinal cord injury (MacKay-Lyons, 2002). In post stroke patients, there is often hemiparesis, with abnormal control of one lower limb producing an asymmetrical gait pattern. In a hemiparetic patient, BWSTT creates a partial unloading of the lower extremities. Reduced load on the paretic lower extremity results in a straighter trunk and knee alignment during the weight bearing phase (Laufer et al., 2001; Lindquist et al., 2007; Lam et al., 2009). Further, due to movement of treadmill, there is a decrease in double-limb support time (stance
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97 sub-acute (within 6 weeks of stroke onset) post stroke subjects. After treatment (BWSTT and over ground training), all patients were able to walk. Both groups (experimental group; n Z 52 and control group; n Z 45) showed improvement in all of the outcome measures (Motricity Index, trunk control test, Barthel index, functional ambulation categories, 10-m and 6-min walk tests, and walking handicap scale) at the end of the treatment and at the follow-up. However, no difference was seen between the groups after the treatment and at the follow-up. Thus, more research is needed to validate the present evidence for effectiveness of BWSTT in chronic and subacute stroke patients (Laufer et al., 2001; Moseley et al., 2005; Franceschini et al., 2009). Studies are also warranted in subjects with the acute stroke (McCain and Smith, 2007). However, with the available evidence, BWSTT may be considered as a standard gait training protocol for the chronic stroke survivors with the gait dysfunction along with the usual movement therapy methods.
Robotic-assisted training Robotic-assisted stroke rehabilitation has been developed during the last two decades (Prange et al., 2006). Robots can provide intensive, reproducible, and task-specific movement therapy. They are also able to address a wide range of treatment needs via active, assistive, or resisted exercise (Fasoli et al., 2004). Robotic training involves two interacting processes: the patient trying to move and the robot assisting or resisting the movements during repetitive practice. It can: provide movement therapy for long time periods, in a consistent & precise manner, with reduced fatigue be programmed to perform in different modes of assistance for the client such as passive (full assistance), active assistive (partial assistance) and active (no assistance) with a single click measure & record a range of behaviors in parallel with the therapeutic applications (Takahashi et al., 2008). be coupled with a virtual environment technology (discussed later) to increase motivation of the client (Mirelman et al., 2009). Further, robotic devices have programmable forceproducing ability, which can replicate some features of a therapist’s manual assistance, allowing patients to semiautonomously practice movement (Kahn et al., 2006). However, some of its features such as mechanical manipulation cannot be replicated by the therapists due to their limited speed, sensation, strength, and repeatability of the neuromuscular system (Lum et al., 2002; Kahn et al., 2006). There are various commercial types of Robotic system. Most of the available types are mainly for the upper limb training such as the Assisted rehabilitation and measurement (ARM) guide, Mirror image movement enabler (MIME), MIT Manus, Hand wrist assistive rehabilitation device (HWARD) while few like Lokomat, Robotic-assisted gait training (RAGT) device are also available for the gait training (Kahn et al., 2006; Prange et al., 2006; Richards et al., 2008a; Takahashi et al., 2008; Marchal-Crespo and Reinkensmeyer, 2009).
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phase), increase in single-limb support time (swing phase) and increase in walking speed (Laufer et al., 2001; Enzinger et al., 2009). This provides an environment for specific and repetitive training for walking (Lindquist et al., 2007). This type of specific and repetitive learning is hypothesized to induce neuroplasticity and associated motor recovery (Schmidt, 2005). Though gait control has more of a subcortical contribution through CPGs (MacKay-Lyons, 2002), BWSTT training is associated with bilateral cortical activation changes in chronic stroke. It was found to increase brain activity in the bilateral primary sensorimotor cortices, the cingulate motor areas, and the caudate nuclei bilaterally and in the thalamus of the affected hemisphere (Enzinger et al., 2009). This may be due to the requirement of motor control in response to environmental demand, position sense and balance during walking, which are being controlled by brain (Nielsen, 2003). Animal studies have also shown that motor cortex modifies the synergies produced by CPGs during complex demand of locomotion (Drew et al., 2008). BWSTT can be used to manage post stroke gait dysfunction by normal gait programming generated by this novel approach. (Laufer et al., 2001; Gorman, 2007; Lam et al., 2009). Randomized trials of BWSTT have shown improvements in gait parameters such as stride length and singlelimb support in the chronic stroke patients (Laufer et al., 2001; Werner et al., 2002). These studies suggested that the treadmill training may be more effective than the conventional gait training for improving gait parameters such as functional ambulation, stride length, percentage of the paretic single stance period, and muscular activity. Enzinger et al. (2009) investigated walking ability after 4 weeks of BWSTT in 18 chronic patients (mean age, 59.9 13.5 years) with mild to moderate paresis and functional ambulation category range, 3e5. Walking endurance improved after the training (2-min timed walking distance: from 105.1 38.1 m to 121.5 39.0; p < 0.0001). BWSTT has also been shown to be effective in conjunction with functional electrical stimulation, a method of augmenting insufficient muscle force by predetermined frequencies and amplitudes of electrical currents (Bogey and Hornby, 2007; Lindquist et al., 2007). Although independent studies have shown significant motor and functional improvement, in a Cochrane review it was found that there was not enough evidence to determine the effects of the treadmill training (Moseley et al., 2005). In their multicentre randomized controlled trial, Nilsson et al. (2001) studied the effect of BWSTT and walking training on the ground at an early stage of rehabilitation in 73 post stroke patients. However, there was no statistically significant difference found between the groups at discharge or at the 10-month follow-up with regard to the functional independence measure, walking velocity, functional ambulation category, Fugl-Meyer assessment, and Berg’s balance scale. Similarly, Suputtitada et al. (2004) also did not find any statistically significant difference between the BWSTT and control group, after a 4-week training period with regard to floor walking velocities and functional balance. It was an observer blinded, randomized controlled trial with 48 chronic stroke patients. Franceschini et al. (2009) also conducted a single-blind, randomized, controlled trial with a 6-month follow-up with
533
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534 Cortical reorganization and associated motor recovery of chronic stroke patients can be enhanced by a robot-aided therapy (Prange et al., 2006; Takahashi et al., 2008). fMRI changes indicate the potential benefit of robotic training in inducing cortical plasticity in the chronic stroke patients (Mintzopoulos et al., 2008). In response to the HWARD robotic-assisted training, fMRI changes showed the significant increase in the sensorimotor cortex activation across the period of therapy (p < 0.05) (Takahashi et al., 2008). Takahashi et al. (2008) also determined the effect of the HWARD on motor function. Post treatment, significant gains were found in the action research arm test and arm motor Fugl-Meyer score (p < 0.0005 & 0.0001, respectively). Robotic-assisted therapy is useful in facilitating motor control (muscle activation patterns, selectivity, and speed of movement) and has long-term effects of several months to several years (Prange et al., 2006). However, no consistent effect on the improvement in functional abilities has been reported (Prange et al., 2006). Though in its infancy, preliminary evidence of the robotic-assisted training shows no adverse effect (Prange et al., 2006). However, it is not clear whether this therapy improves outcome to a greater extent than the conventional therapy (Richards et al., 2008a). Further, considering the high cost value of the robotic devices, its use in a typical clinical practice is limited (Marchal-Crespo and Reinkensmeyer, 2009). More studies are needed to examine the substantial benefits from this hi-technology based therapy program.
Virtual training Virtual reality (VR) is another new promising computer assisted technology to promote motor recovery in the stroke patients (You et al., 2005). It is an interactive intervention approach, which involves real-time simulation of an environment, scenario or activity that allows user interaction. Multiple sensory channels are also used to provide threedimensional and sensorial feedbacks (Crosbie et al., 2007). Using VR, intensity of practice and sensory feedback (visual, auditory and sometimes touch) can be systematically manipulated to provide the most appropriate, individualized real-life motor training (Merians et al., 2002). For example, a virtual environment of outdoor game in which auditory feedback in the form of clapping is provided on every correct motor performance. VR training programs are designed to be either task specific or meaningful to the participant, which are important in maximizing motor learning (Henderson et al., 2007). There are various types of Virtual reality devices/systems available in neurorehabilitation practice (Adamovich et al., 2009). In general, there are two types of VR, immersive and non-immersive. Fully immersive VR can use large screen projection where the environment is projected on a concave surface to create the sense of immersion. In a non-immersive VR, users interact to different degrees with the environment displayed on a computer screen, with or without interface devices such as a computer mouse (Henderson et al., 2007). IREX VR system is an immersive type of VR, enables a patient to move freely in the real world while allowing manipulation of the virtual objects and navigation in the 3-dimension virtual world. For example, snowboard
K.N. Arya et al. games with virtual environments to facilitate the lower limb range of motion, balance, mobility, stepping, and ambulation skills (You et al., 2005). Nintendo Wii introduced a new style of non-immersive VR by using a wireless controller that interacts with the player through a motion detection system. The controllers use embedded acceleration sensors that can respond to changes in direction, speed, and acceleration to enable participant’s wrist, arm, and hand movements to interact with the games (http://www.nintendo.com/wii). VR has been found to induce cortical reorganization and improve associated motor function in the chronic hemiparesis (Piron et al., 2003; You et al., 2005; Jang et al., 2005; Adamovich et al., 2009; Kim et al., 2009). In an RCT, fMRI changes were found to be evident in the corresponding sensorimotor cortex of the chronic stroke patients after locomotor VR training by IREX VR system (You et al., 2005). Also, post VR training, the altered activations in the bilateral primary sensorimotor cortices (SM1s) and contralesional premotor cortex disappeared and significant activation of the ipsilesional SM1 was found (p < 0.05) (Jang et al., 2005). Piron et al. (2003) conducted an RCT with 24 sub-acute stroke patients to study the effect of non-immersive VR system on arm recovery. Though the difference between the groups was not statistically significant, the VR group showed 20.2% and 12.4% improvements in the Fugl-Meyer assessment and functional independence measure scale mean scores respectively. The control group showed significant but smaller score improvements: 11.3% and 9.1%, respectively. However, the evidence on the effectiveness of using VR for upper extremity recovery is limited. Very few goodquality RCTs for the upper extremity have been conducted (Jang et al., 2005; Henderson et al., 2007; Kim et al., 2009). Kim et al. (2009) examined the effect of GAITRite VR system on balance and gait function in patients with 24 chronic stroke patients. The experimental group improved on the Berg balance scale scores, gait velocity, cadence, step time, step length, and stride length (p < 0.05), compared with the controls. Furthermore, VR training has been combined with the robotic therapy and has demonstrated improvement in motor function, balance and ambulation (Mirelman et al., 2009). The combination of the robotic and virtual Reality devices allows manipulation of the duration, intensity, and feedback of training programs. These characteristics of training were reported to be closely related to recovery, reorganization, and cortical plasticity after stroke (Mirelman et al., 2009). VR is a novel and costly approach; further trials are needed to justify its effectiveness. Technological research is required to develop VR programs, specifically for the functional tasks or activities of relevance to the patients. Such programs are assumed to induce better cortical reorganization.
Conclusion For many years, the human brain was characterized as hard wired, which led to the development of therapeutic methods for compensation only. Recent evidence, both in neuroscience and neurorehabilitation, has shown that the human brain is neuroplastic. This feature of the brain contributes to recovery following stroke and can be exploited through
specific treatment methods based on movements. Such therapeutic methods for improving motor and functional recovery should be applied in neurorehabilitation practice, but these innovative approaches should only be applied with consideration of the evidence, cost effectiveness and participation of the client. Irrespective of sophistication in technology, treatment methods driving recovery at motor as well as neural level should be selected. Research must be continued in the direction of movement therapy induced cortical reorganization and related motor recovery for rehabilitation of post stroke patients.
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536 Kahn, L.E., Lum, P.S., Rymer, W.Z., Reinkensmeyer, D.J., 2006. Robot-assisted movement training for the stroke-impaired arm: does it matter what the robot does? J. Rehabil. Res. Dev. 43 (5), 619e630. Kim, J.H., Jang, S.H., Kim, C.S., Jung, J.H., You, J.H., 2009. Use of virtual reality to enhance balance and ambulation in chronic stroke: a double-blind, randomized controlled study. Am. J. Phys. Med. Rehabil. 88 (9), 693e701. Kleim, J.A., Jones, T.A., 2008. Principles of experience-dependent neural plasticity: implications for rehabilitation after brain damage. J. Speech Lang. Hear Res. 51 (1), S225eS239. Krakauer, J.W., 2006. Motor learning: its relevance to stroke recovery and neurorehabilitation. Curr. Opin. Neurol. 19 (1), 84e90. Lacourse, M.G., Turner, J.A., Randolph-Orr, E., Schandler, S.L., Cohen, M.J., 2004. Cerebral and cerebellar sensorimotor plasticity following motor imagery-based mental practice of a sequential movement. J. Rehabil. Res. Dev. 41 (4), 505e524. Lam, T., Luttmann, K., Houldin, A., Chan, C., 2009. Treadmillbased locomotor training with leg weights to enhance functional ambulation in people with chronic stroke: a pilot study. J. Neurol. Phys. Ther. 33 (3), 129e135. Langhammer, B., Stanghelle, J.K., 2000. Bobath or motor relearning programme? A comparison of two different approaches of physiotherapy in stroke rehabilitation: a randomized controlled study. Clin. Rehabil. 14 (4), 361e369. Laufer, Y., Dickstein, R., Chefez, Y., Marcovitz, E., 2001. The effect of treadmill training on the ambulation of stroke survivors in the early stages of rehabilitation: a randomized study. J. Rehabil. Res. Dev. 38 (1), 69e78. Levin, M.F., Kleim, J.A., Wolf, S.L., 2009. What do motor "recovery" and "compensation" mean in patients following stroke? Neurorehabil. Neural Repair 23 (4), 313e319. Lin, K.C., Wu, C.Y., Liu, J.S., Chen, Y.T., Hsu, C.J., 2009. Constraint-induced therapy versus dose-matched control intervention to improve motor ability, basic/extended daily functions, and quality of life in stroke. Neurorehabil. Neural Repair 23 (2), 160e165. Lindquist, A.R., Prado, C.L., Barros, R.M., Mattioli, R., da Costa, P.H., Salvini, T.F., 2007. Gait training combining partial body-weight support, a treadmill, and functional electrical stimulation: effects on poststroke gait. Phys. Ther. 87 (9), 1144e1154. Liu, K.P., Chan, C.C., Lee, T.M., Hui-Chan, C.W., 2004. Mental imagery for promoting relearning for people after stroke: a randomized controlled trial. Arch. Phys. Med. Rehabil. 85 (9), 1403e1408. Luft, A.R., McCombe-Waller, S., Whitall, J., et al., 2004. Repetitive bilateral arm training and motor cortex activation in chronic stroke: a randomized controlled trial. JAMA 292 (15), 1853e1861. Lum, P., Reinkensmeyer, D., Mahoney, R., Rymer, W.Z., Burgar, C., 2002. Robotic devices for movement therapy after stroke: current status and challenges to clinical acceptance. Top. Stroke Rehabil. 8 (4), 40e53. MacKay-Lyons, M., 2002. Central pattern generation of locomotion: a review of the evidence. Phys. Ther. 82 (1), 69e83. Maldonado, M.A., Allred, R.P., Felthauser, E.L., Jones, T.A., 2008. Motor skill training, but not voluntary exercise, improves skilled reaching after unilateral ischemic lesions of the sensorimotor cortex in rats. Neurorehabil. Neural Repair 22 (3), 250e261. Marchal-Crespo, L., Reinkensmeyer, D.J., 2009. Review of control strategies for robotic movement training after neurologic injury. J. Neuroeng Rehabil. 16 (6), 20. Markus, T.M., Tsai, S.Y., Bollnow, M.R., et al., 2005. Recovery and brain reorganization after stroke in adult and aged rats. Ann. Neurol. 58 (6), 950e953. McCain, K.J., Smith, P.S., 2007. Locomotor treadmill training with body-weight support prior to over-ground gait: promoting
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PREVENTION & REHABILITATION - REHABILITATION
Neurorehabilitation Neuroplasticity
Journal of Bodywork & Movement Therapies (2011) 15, 538e541
available at www.sciencedirect.com
journal homepage: www.elsevier.com/jbmt
CLINICAL METHODS
A case study utilizing Vojta/Dynamic Neuromuscular Stabilization therapy to control symptoms of a chronic migraine sufferer PREVENTION & REHABILITATION e CLINICAL METHODS
David D. Juehring, DC, DACRB*, Michelle R. Barber, BA, MSW, DC Palmer Chiropractic Rehabilitation and Sports Injury Department, Palmer College of Chiropractic, 1000 Brady Street, Davenport, IA 52803, United States Received 10 November 2010; received in revised form 21 December 2010; accepted 14 January 2011
KEYWORDS Migraine; Chronic; Treatment; Vojta; Dynamic Neuromuscular Stabilization
Summary Introduction: Migraine is a complex disorder of the brain characterized by severe headache, photophobia, phonophobia, and nausea. This case report demonstrated the reduction of a 49-year-old female’s chronic migraine symptoms after 12 weeks of Vojta/Dynamic Neuromuscular Stabilization (DNS) therapy. Methods: Vojta/DNS treatment occurred either in the office or at home over a 12-week period. Symptoms were tracked via a patient diary, a VAS pain scale, and a Headache Disability Index (HDI). Results: The patient’s migraine symptoms were typically of 3 days duration, a frequency of 8e10 times per month, and an intensity of 10/10 on a VAS pain scale. After a 12-week trial of Vojta/DNS care, subjective improvements were noted, with a reduction in frequency to 1e2 times per month, duration of 12 h at most, and decreased intensity to a 2/10 on a VAS pain scale. HDI scores dropped from 48% to 34%. Discussion: This therapy reduced the patient migraine sysmptoms in frequency, duration and intensity. This therapy is not well-known in North America despite its use for over 40 years in Europe. Conclusion: This case demonstrated that Vojta/DNS treatment over a 12-week period helped manage the patient’s migraines and could be a possible treatment option for future research. ª 2011 Elsevier Ltd. All rights reserved.
* Corresponding author. Tel.: þ1 563 884 5455; fax: þ1 563 884 5865. E-mail address:
[email protected] (D.D. Juehring). 1360-8592/$ - see front matter ª 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jbmt.2011.01.019
Introduction Migraine is a complex disorder of the brain which is typically characterized by spontaneous attacks of unilateral, throbbing headaches which are often aggravated by movements (Messlinger, 2009), along with non-headache symptoms including photophobia, phonophobia, and nausea (Sprenger and Goadsby, 2009). These characteristic symptoms are found in all types of migraine, the most common types being migraine without aura, fo0llowed by migraine with aura (Messlinger, 2009). It has been found that nearly half the world’s population has an active headache disorder and according to the American Migraine Prevalence and Prevention study of 2004 (Lipton et al., 2007), migraine in particular has a prevalence of 12% in the general population, 18% in women, and 6% in men (Robbins and Lipton, 2010). Migraine is reported to be among the top 20 causes of disability worldwide, as more than half of those affected have such severe symptoms that they cannot function normally in their routine daily activities, including work, school, and social activities (Brandes, 2009). 48.2% of migraineurs reported some level of impairment, 22.1% were severely disabled, and more than half reported the need for bed rest (Lipton et al., 2007). In addition, during the periods between attacks, worry, stress, and expectation of future attacks may also lead to functional impairment, a phenomenon known as the interictal burden (Brandes, 2009). It is commonly noted that migraine attacks may be precipitated by a number of factors, which are often termed “migraine triggers.” Approximately 76% of migraine sufferers report identifiable triggers (Sauro and Becker, 2009). Reported triggers are widely varied, including hormonal changes in women e migraine headache is related to the menstrual cycle in about 60% of female patients (Lambert and Zagami, 2009) e certain foods, missing meals, weather changes, alcohol, and sleep disturbances. Fatigue is the most commonly reported trigger, with stress the second most common (Sauro and Becker, 2009). Additional triggers can include flickering lights, loud noises, strong smells, drugs which deplete the brain of the neurotransmitter serotonin, environmental changes e especially in temperature and barometric pressure e and for many patients no external trigger is apparent at all (Lambert and Zagami, 2009). The variety of triggers and the individual nature of triggers have led to the hypothesis that only some kind of neural event can explain triggering. There is much evidence in the literature at this time to support the notion that migraine is more than a headache disorder, but instead is a pathophysiologically complex disorder that arises from a neurovascular disturbance in the brain itself, and involves modulatory mechanisms in the brainstem, subcortical, and cortical levels to process pain. These processing mechanisms may be abnormal in migraine, which uses otherwise normal neural pathways for pain transmission (Purdy, 2010). As depression travels slowly across the cerebral cortex (cortical spreading depression), trigeminal nerve terminals surrounding the meningeal arteries are stimulated, eliciting a trigeminovascular reflex that explains subsequent vascular changes and headache (Martins, 2009). Migraine sufferers typically try a multitude of interventions in an effort to reduce the frequency and severity of
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their attacks as well as to improve function and reduce disability (Brandes, 2009). There are numerous pharmacological interventions, including beta-blockers, antidepressants, anticonvulsants, calcium channel blockers and serotonin antagonists, but side effects and contraindications because of co-morbidities can complicate treatment (Sprenger and Goadsby, 2009). Over half of the diagnosed migraineurs in the US use OTC analgesics, which are effective in up to 60% of cases (Whyte et al., 2010). Many migraine patients try manual therapies; primary choices are physical therapy, massage, and spinal manipulative therapy (Biondi, 2005). Recent reviews have shown physical therapy is most effective in combination with other therapies such as biofeedback, relaxation training, and exercise (Biondi, 2005). Massage therapy was shown to be beneficial in reducing frequency of migraine attacks, as well as improving perceived stress and coping efficacy (Lawler and Cameron, 2006). There is also some evidence indicating that spinal manipulation has effectiveness similar to a firstline prophylactic prescription medication (amitriptyline) for the prophylactic treatment of migraine (Bronfort et al., 2010). In addition, migraine patients also frequently use complementary and alternative medicine (CAM), with relaxation therapies and chiropractic care being the most common CAM therapies employed (Astin and Ernst, 2002). Additional alternative treatments include: vitamins and minerals such as riboflavin, niacin, and magnesium; supplements such as feverfew, butterbur, and coenzymeQ10; mind-body therapies such as biofeedback, cognitive behavioral therapy, guided imagery, “headache school,” self-hypnosis, meditation, and relaxation training; physical treatments such as acupuncture, massage therapy, physical therapy, and spinal manipulation; and lifestyle modifications such as food and alcohol elimination, aerobic exercise, and sleep hygiene (DynaMed, 1995). Vojta/Dynamic Neuromuscular Stabilization (DNS) is a therapy used predominantly in Europe to manage neurological and musculoskeletal conditions (Laufens et al., 1999; Niethard, 1987; Bo ¨hme and Futschik, 1995; Bauer et al., 1992; Vojta and Peters, 2007). Vojta therapy was developed from 1955 to 1969 by a Czech pediatric neurologist Vaclav Vojta (Bauer et al., 1992; Vojta and Peters, 2007). His treatment approach in the broadest of terms involved utilizing digital pressure on specific points of the body to provide afferent stimulation to evoke genetically predetermined CNS motor programs to address various neurological-based conditions (Vojta and Peters, 2007). Since the mid-nineties, these treatment principles and approaches have since been modified by Pavel Kola ´r, a physiotherapist from the Czech Republic. His modified approach was eventually named Dynamic Neuromuscular Stabilization (Bokarius and Bokarius, 2008). The purpose of this case report is to demonstrate how the Vojta/DNS treatment approach greatly reduced diagnosed migraine symptoms over a 12-week period for a 49-year-old female who had consistently experienced intense frequent symptoms over her last 40 years.
Methods The initial treatments consisted of Vojta/DNS therapy for 10e15 min in a supine position with the patient’s palms
PREVENTION & REHABILITATION e CLINICAL METHODS
A case study utilizing Vojta/Dynamic Neuromuscular Stabilization therapy
PREVENTION & REHABILITATION e CLINICAL METHODS
540 placed down on the treatment table. The patient was positioned supine due the ease of maintaining cervical spine neutral posture. On general patient visual observation of the cervical spine on both standing and supine the patient had a slight left lateral shearing and rotation along with anterior head carriage. It was theorized that this postural aberration may have been the possible cause for the patient’s chronic symptoms. To neutralize this postural issue in the cervical spine, mild long-axis digital pressure was applied at the occiput to help hold the cervical spine in the neutral position while minimizing upper cervical hyperextension. This positioning maximized cervical spinal joint centration, ultimately relaxing overactive cervical muscles and establishing a neutral cervical spine posture. Along with this positioning, firm digital pressure was applied between ribs seven and eight at the mid-clavicular line directed towards the fourth thoracic vertebral body to provide proprioceptive afferent input as part of the treatment approach. Clinical judgment determined daily treatment times based upon a reduction of cervical tension to enhance neutral cervical posture; treatment times were longer in the initial stages of care as compared to the end stages of daily treatment times. Care was taken to apply firm pressure without causing a painful stimulus to the patient and that digital pressure did not cause any lateral bending, rotation, or shear in the thoracic spine to maintain a neutral spine. The above treatment procedure was performed on one side of the body for half the treatment time, then switched to the contralateral side based upon the patient’s cervical asymmetries (Kola ´r, 2007). During the course of treatment, the patient’s initial Vojta/DNS treatments started at 2e3 days of treatments each week for the first three weeks, then tapered to one treatment every 2e3 weeks until the last month of care when the patient was only seen once. At three weeks of care it was apparent that positive outcomes were obvious by patient report, at which time the patient’s spouse was trained to provide basic care at home on non-office days to help progress the continual drop in the patient’s frequency, duration and intensity of symptoms. For home care, it was recommended that the care be performed daily at the same duration and position used in the office. It was also recommended to perform the care on a firm surface such as the floor similar to the hardness of the office treatment tables. The patient’s symptoms pertaining to these parameters were monitored per patient visit and via a daily diary kept by the patient. A Headache Disability Index and VAS pain scale was utilized on the initial visit and only again at week 12 comparison without intermediate assessments.
Results Prior to treatment, the patient reported symptoms of intense headaches, light sensitivity, vision disturbances, vomiting, and fatigue which occurred 8e10 times per month and lasted consistently for three days. After a 12week clinical trial, subjective improvements were noted, with a reduction of symptom frequency of one to two times a month, lasting at most 12 h in duration and with an eightpoint reduction on a ten-point VAS pain scale. Headache Disability Index scores dropped from 48% to 34%. At one
D.D. Juehring, M.R. Barber time during therapy, the patient was without migraines for a three-week period, which she recalled had never happened before.
Discussion Vojta/Dynamic Neuromuscular Stabilization therapy has been utilized in the management of neurological and musculoskeletal conditions (Laufens et al., 1999; Niethard, 1987; Bo ¨hme and Futschik, 1995; Bauer et al., 1992; Vojta and Peters, 2007) throughout Europe, though it is not well known as a care option in North America. Vojta therapy has been applied roughly from the 1950s to present and was initially developed by the pediatric neurologist Vaclav Vojta (Bauer et al., 1992; Vojta and Peters, 2007). Through his clinical observation of the development of healthy infants, he noted a natural progression that they underwent for functional movements. He believed this was not a learned behavior but a genetically predetermined program that was expressed by the CNS as it developed (Vojta and Peters, 2007). Vojta’s clinical approach to less-than-ideal development movement patterns was to manually stimulate specific zones of the body to evoke genetically predetermined efferent motor expressions of the CNS to regain ideal movement patterns. This program was defined as “reflex locomotion” (Vojta and Peters, 2007). This approach was eventually applied to adults for numerous neuromusculoskeletal conditions. The principles and treatment methods were later expanded upon by Pavel Kola ´r, Director of the Rehabilitation Department at University Hospital Motol, in Prague, Czech Republic. Dr. Kola ´r added active components and loaded positioning to these methods to address dysfunctions and coined the name Dynamic Neuromuscular Stabilization (DNS) (Bokarius and Bokarius, 2008). In this case, the patient had been diagnosed with migraines by two neurologists and three MRIs spanning a twenty-year period. She tried many treatment approaches with nominal results. She had tried upper cervical specific chiropractic care for an approximately three-month period of time with an occasional mild reduction of symptoms which would quickly return within a week. Also she had tried soft tissue release for two visits to address the hyperflexion of the upper cervical spine which greatly intensified the frequency, intensity and length of her migraine symptoms. The therapy she most utilized was OTC pain and headache medicines with only mild temporary results. She reported having “debilitating” migraines once to twice a year that would be relieved by Imitrex (triptan) injections. Unfortunately, there exists little published Vojta/DNS literature on the concepts and treatment approaches, with even less articles written in English. The Vojta/DNS approach was considered in this case due to its proposed speculative ability to address global neurological disturbances at a subcortical level, based upon the concepts and treatment possibilities presented in printed materials (Laufens et al., 1999; Niethard, 1987; Bo ¨hme and Futschik, 1995; Bauer et al., 1992; Vojta and Peters, 2007; Kola ´r, 2007). With the theories of migraine as a pathophysiologically complex disorder that arises from a neurovascular disturbance in the brain itself, and involves modulatory mechanisms in the brainstem, subcortical and cortical
levels to process pain (Purdy, 2010), the authors postulated that it would appear worthy of a clinical trial for this patient’s particular condition utilizing Vojta/DNS therapy. Vojta/DNS care was also considered as a possible method of treatment due to her responses to other previous neuromuscular care. Although negative with the soft tissue treatment and only slightly positive with the upper cervical adjustive care the authors speculated that a treatment in the cervical spine given the postural asymmetries could be minimized or eliminated from the neuromuscular impacts suggested in published articles (Bokarius and Bokarius, 2008; Laufens et al., 1999; Kola ´r, 2007). The supine position was utilized to help facilitate global neutral positioning of the cervical spine to address left lateral shear and rotation along with anterior head carriage to reduce cervical postural asymmetries in hopes to impact symptoms. The stimulation point and body posture utilized is considered the most effective at facilitating sagittal stability (Vojta and Peters, 2007). Other beneficial reasons for the choice of this treatment position were its comfort for the patient and the relative ease of educating the patient’s husband to perform the appropriate positioning and treatment at home for an effective therapeutic response by a lay person.
Conclusion This case demonstrated that Vojta/DNS treatment over the course of 12 weeks helped manage the patient’s migraines. This treatment approach demonstrated an effect on this patient’s condition by reducing the patient’s reported frequency, duration and intensity of symptoms along with reduced VAS pain scale and Headache Disability Index scores. Migraine is a disorder of the brain characterized by a complex sensory dysfunction, and as such, interventional neuromodular approaches with neural targets are most promising (Sprenger and Goadsby, 2009). Looking at migraine from a neurobiological approach, it would seem that any approaches which involve change or perturbation of the abnormal processes could reduce migraine symptoms (Purdy, 2010). The positive outcomes achieved in this case using the Vojta/DNS approach to addressing neurological disturbances have promising potential. Further research is needed to evaluate this clinical approach and its success in treating other patients with migraine disorders.
Conflict of interest The authors declare that they have no conflict of interest.
References Astin, J.A., Ernst, E., 2002. The effectiveness of spinal manipulation for the treatment of headache disorders: a systematic review of randomized clinical trials. Cephalalgia 22 (8), 617e623.
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Bauer, H., Appaji, g, Mundt, D., 1992. Vojta Neurophysiologic Therapy. Indian Journal of Pediatrics 59, 37e51. Biondi, D., 2005. Physical treatments for headache: A structured review. Headache (45), 738e746. Bo ¨hme, B., Futschik, M., 1995. Verbesserte Lungenfunktion nach Vojta-Brustzonen-Reiz bei bronchopulmonaler Dysplasie. Monatsschrift fu ¨r Kinderheilkunde 143, 1231e1234 (in German). Brandes, J.L., 2009. Migraine and functional impairment. CNS Drugs 23 (12), 1039e1045. Bronfort, G., Haas, M., Evans, R., Leininger, B., Triano, J., 2010. Effectiveness of manual therapies: the UK evidence report. Chiropractic and Osteopathy 18:3. Bokarius, A.V., Bokarius, V., 2008. Long-term efficacy of dynamic neuromuscular stabilization in treatment of chronic musculoskeletal pain. In: Abstract of the 12th World Congress on Pain, Glasgow, Scotland. DynaMed [Internet], 1995. EBSCO Publishing, Ipswich (MA) [cited 2010 Nov 2]. Available from: http://www.ebscohost.com/ dynamed/. Kola ´r, P., 2007. Facilitation of agonist-antagonist activation by reflex stimulation methods. In: Liebenson, C. (Ed.), Rehabilitation of the Spine, second ed. Lippincott/Williams & Wilkins, Philadelphia. Lambert, G.A., Zagami, A.S., 2009. The mode of action of migraine triggers: a hypothesis. Headache 49 (2), 253e275. Laufens, G., Poltz, W., Prinz, E., Reimann, G., Schmiegelt, F., 1999. Verbesserung der Lokomotion durch kombinierte Laufband-/Vojta-Physiotherapie bei ausgewa ¨hlten MS-Patienten. Physikalische Medizin. Rehabilitationsmedizin, Kurortmedizin 9, 187e189 (in German). Lawler, S.P., Cameron, L.D., 2006. A randomized, controlled trial of massage therapy as a treatment for migraine. Annals of Behavioral Medicine 32 (1), 50e59. Lipton, R.B., Bigal, M.E., Diamond, M., Freitag, F., Reed, M.L., Stewart, W.F.AMPP Advisory Group, 2007. Migraine prevalence, disease burden, and the need for preventive therapy. Neurology 68 (5), 343e349. Martins, I.P., 2009. Migraine. Acta Me ´dica Portuguesa 22 (5), 589e598 (in Portugese). Messlinger, K., 2009. Migraine: where and how does the pain originate? Experimental Brain Research 196 (1), 179e193. Niethard, F.U., 1987. Vorla ¨ufige Behandlung angeborener Hu ¨ftluxation durch physikalische Therapie auf Basis der Neurophysiologie. Zeitschrift fu ¨die und Unfallchirurgie 125, ¨r Orthopa 28e34 (in German). Purdy, R.A., 2010. Migraine is curable! Neurologic Sciences 31 (Suppl. 1), S141eS143. Robbins, M.S., Lipton, R.B., 2010. The epidemiology of primary headache disorders. Seminars in Neurology 30 (2), 107e119. Sauro, K.M., Becker, W.J., 2009. The stress and migraine interaction. Headache 49 (9), 1378e1386. Sprenger, T., Goadsby, P.J., Nov 16 2009. Migraine pathogenesis and state of pharmacological treatment options. BMC Medicine 7, 71. Vojta, V., Peters, A., 2007. Das Vojta-Prinzip Muskelspiele in Reflexfortbewegung und Motorischer Ontogenese, third ed. Springer Medizin Verlag, Heidelberg. Whyte, C., Tepper, S.J., Evans, R.W., 2010. Expert opinion: rescue me: rescue medication for migraine. Headache 50 (2), 307e313.
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Journal of Bodywork & Movement Therapies (2011) 15, 542e544
available at www.sciencedirect.com
PREVENTION & REHABILITATION e SELF MANAGEMENT: PATIENT SECTION
journal homepage: www.elsevier.com/jbmt
PREVENTION & REHABILITATION e SELF MANAGEMENT: PATIENT SECTION
Functional training with the kettlebell Craig Liebenson, DC* L.A. Sports & Spine, 10474 Santa Monica Blvd, #304, Los Angeles 90025, USA There are various types of traditional strengthening exercises such as Nautilus, free weights, pulleys, etc. Most follow a certain rule of isolating individual muscles and making them bigger and stronger. Kettlebells have been used in Russia for a long time, but are new in most other parts of the world. What is unique about kettle bells is that due to their shape they provide an unstable force which the body has to learn to handle. It is not merely a matter of building strength, but learning how to control e or stabilize e the weight. In this way kettlebell (KB) exercises are ideal for functional training that mirrors the challenges one faces in day to day activities (McGill, 2011). Many people with persistent pain have trouble carrying objects. Carrying a briefcase, grocery bag, or baby requires both strength and stability. Strength is needed to lift the object, while stability is necessary to maintain balance or equilibrium during the task. Unfortunately, in training stability is usually ignored even though it is the more decisive of the two components in determining your injury risk. The KB exercises shown here are excellent for training both strength and stability during carrying activities. Key points are highlighted for each exercise to ensure that stability is not sacrificed while trying to build as much strength as possible. Each of the exercises shown here focus on hip and trunk stability in what is called the frontal plane. Whereas popular exercises like sit-ups, chest press, or bicep curls train forward or backward bending motions, these carrying exercises work stability in a side to side direction. This is of great importance since instability in the frontal plane leads to excessive side to side motion which has been shown to cause injury to the knee or low back (see Fig. 1).
* Tel.: þ1 31047 02909; fax: þ1 31047 03286. E-mail address:
[email protected]. URL: http://craigliebenson.com. 1360-8592/$ - see front matter ª 2011 Published by Elsevier Ltd. doi:10.1016/j.jbmt.2011.07.003
Suitcase Carry Start with this exercise Hold a KB in your hand like it is a suitcase (see Figure 2) Take about 20 steps at a normal or somewhat brisk pace Then, switch hands Start with a light weight such as 5 kg
Figure 1
Carrying a grocery bag (a) unstable (b) stable.
Figure 2
Suitcase Carry.
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Figure 3
Waiter Carry.
Key Point: Avoid excessive side to side swaying of the body Waiter Carry Grip the KB in your hand like it is a barbell (see Figure 3) Take about 20 steps at a normal or somewhat brisk pace Then, switch hands Start with a light weight such as 5 kg Key Point: Avoid excessive shrugging of your shoulder on the side of the weight Overhead Carry Grip the KB in your hand while reaching your arm overhead as far as possible (see Figure 4) Take about 20 steps at a normal or somewhat brisk pace Then, switch hands Start with a light weight such as 5 kg Key Point: Avoid leaning to the side when walking with the KB Bottoms Up Carry Hold the KB by the handle firmly and turn it upside down so that it’s bottom is facing up (see Figure 5a) Keep your elbow in at your side and slightly “brace” (i.e. tighten) your core to stabilize your body Take about 20 steps at a normal or somewhat brisk pace Then, switch hands Start with a light weight such as 5 kg
Figure 4
Overhead Carry.
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Functional training with the kettlebell
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C. Liebenson
Figure 5
Bottoms Up Carry (a) correct arm position (b) incorrect.
Key Point: Avoid holding the KB away from your body (see Figure 5b) The Farmer’s Walk Hold a KB in each hand with arms extended down at your side (see Figure 6)
Take about 20 steps at a normal or somewhat brisk pace Start with a light weight such as 5 kg Key Point: Avoid excessive swaying side to side while walking
Reference McGill, S., 2011. Ultimate Back Fitness and Performance, fourth edition. Back Fit Pro.
Figure 6
Farmer’s Walk.
