Research Review By Dr. Michael Haneline©

Date Posted:

Mar. 2009

Study Title:

Chiropractic management of myofascial trigger points and myofascial pain syndrome: A systematic review of the literature

Authors:

Vernon H, Schneider M.

Author's Affiliations:

Canadian Memorial Chiropractic College, Toronto, Ontario, Canada.

Publication Information:

Journal of Manipulative & Physiological Therapeutics 2009; 32:14-24.

Background Information:

Myofascial trigger points (TrPs) and their role in myofascial pain syndrome (MPS) is a common and acknowledged component of musculoskeletal clinical practice. In fact, MPS is considered the leading diagnosis among pain management specialists as well as general practitioners treating pain patients. The concept of myofascial tenderness has been discussed in the chiropractic and manual therapy disciplines for many years, especially by Nimmo in his work on the Receptor-tonus technique. In addition, Hammer has written a widely accepted textbook on this topic (1).

Accordingly, the purpose of this study was to review the most commonly used treatment procedures for MTrPs and MPS in chiropractic specifically.

Pertinent Results:

There were 112 articles identified in the literature search, including 2 systematic reviews and 14 randomized controlled trials (RCTs). The search also generated a number of case reports, 6 clinical reviews, and 1 publication of practice guidelines on manual therapies.

The included systematic reviews were of fairly high quality: Oxford Scale = 1a evidence and SIGN quality rating = 2+.

Most of the studies in these systematic reviews only considered the immediate effects of various therapies on pain and tenderness. One study investigated treatment effects in the short-term (i.e., over 5 treatments) and 2 followed the subjects for 6 months.

The types of interventions that were used in these studies included:
  • spray and stretch
  • soft tissue massage
  • ischemic compression
  • occipital release exercises
  • strain/counterstrain
  • myofascial release
One of the reviews by Fernandez de las Penas et al.(2) concluded that “the hypothesis that manual therapies have specific efficacy beyond placebo in the management of MPS caused by MTrPs is neither supported or refuted by the research to date.”

The practice guidelines from the Institute for Clinical Systems Improvement that were included in this review made no recommendation for physical (manual) therapies in the treatment of MPS or TrPs.

The authors found 3 RCTs in addition to those identified by previous reviewers. The Oxford Scale ratings were fairly high for these studies, although they all only investigated the immediate effect of the interventions on local muscular pain thresholds. Spinal manipulation was found to result in a statistically significant increase of pain thresholds as compared with mobilization in the cervical and dorsal muscles, but not in the lumbopelvic soft tissues.

The outcomes of the “immediate” trials demonstrated effectiveness in reducing tenderness for spinal manipulation, spray and stretch, ischemic compression, transverse friction massage, and strain/counterstrain. However, mobilization failed to show any significant changes in tenderness scores vs. controls. Based on this evidence, the authors concluded that there is moderately strong evidence to support the use of some manual therapies in the immediate relief of TrP tenderness.

Longer term effects in reducing TrP tenderness were demonstrated for osteopathic manipulation and ischemic compression (3-5 days), as well as strain/counterstrain (long-term effects [6 months]). Massage was shown to have a limited effect in the long-term. Based on this evidence, the authors concluded that there is limited support for the use of manual therapies over longer periods of time in the treatment TrPs and MPS.

The authors were critical of the clinical reviews that were located because, although they endorsed the use of manual therapies, they were generally not founded on evidence. They asserted that none of the clinical reviews provided a single reference to a clinical trial to support their positions. Given that most of the clinical reviews were prepared by renowned experts in the field of myfascial pain, there is a disparity between the “consensus on the use and types of manual therapies in treating TrPs vs the evidence from the published literature.”

In addition to manual therapies, this review also considered “other” therapies that are sometimes used by chiropractors to treat TrPs and MPS (e.g. electrotherapy and ultrasound). Two published reviews were included and the authors were able to find several other RCTs on acupuncture that were not located in previous reviews. In total, 29 RCTs were included. The authors provided Clinical Practice Recommendations regarding the treatment of TrPs and MPS using “other” therapies which are listed in the next section.

Clinical Application & Conclusions:

Recommendations for the treatment of TrPs and MPS using manual therapies are as follows:
  • There is moderately strong evidence to support the use of some manual therapies (manipulation, ischemic pressure) in providing immediate relief of pain at MTrPs. (Rating B)
  • There is limited evidence to support the use of some manual therapies in providing long-term relief of pain at MTrPs. (Rating C)
Recommendations for the treatment of TrPs and MPS using other conservative therapies (non-manipulation) are as follows:
  • There is strong evidence that laser therapy (various types of lasers) is effective in the treatment of MTrPs and MPS. (Rating A)
  • There is moderately strong evidence that TENS is effective in the short-term relief of pain at MTrPs. (Rating B)
  • There is moderately strong evidence that magnet therapy is effective in the relief of pain at MTrPs and in MPS. (Rating B)
  • There is moderately strong evidence that a course of deep acupuncture to MTrPs is effective in the treatment of MTrPs and MPS for up to 3 months. (Rating B)
  • There is limited evidence for the effectiveness of frequency modulated neural stimulation (FREMS), high-voltage galvanic stimulation (HVGS), electrical muscle stimulation (EMS), and interferential current (IFC) in the treatment of MTrPs and MPS. (Rating C)
  • There is conflicting evidence that US is no more effective than placebo or is somewhat more effective than other therapies in the treatment of MTrPs and MPS. (Rating C)

Study Methods:

This was a systematic review that was conducted during the process of developing the Council on Chiropractic Guidelines and Practice Parameters (CCGPP) Best Practices Documents. The authors intended to only include studies of chiropractic treatments (manual therapy and other conservative therapies) that were not incorporated into the other CCGPP reviews.

Numerous databases (9 total) were searched using a wide-range of query terms. In order to ensure thoroughness, several secondary searches were conducted (e.g., manual searches of the reference sections of included articles).

The Oxford Rating Scale and the Scottish Intercollegiate Guidelines Network (SIGN) Checklist were used to rate the evidence level and quality of the included studies. The scale and checklist are as follows:

The Oxford Rating Scale
1a: Systematic review, with homogeneity of RCT’s.
1b: Individual RCT with narrow confidence interval.
1c: All or none.
2a: Systematic review, with homogeneity of cohort studies.
2b: Individual cohort study (including low quality RCT; eg b80% follow-up).
2c: “Outcomes Research”; Ecological studies.
3a: Systematic review with homogeneity of case-control studies.
3b: Individual case-control study.
4: Case-series (and poor quality cohort and case-control studies).
5: Expert opinion without explicit critical appraisal, or based on physiology, bench research or “first principles”.

The SIGN Checklist:
Accurately reproduced below from the SIGN website (3):
"++": All or most of the criteria have been fulfilled. Where they have not been fulfilled the conclusions of the study or review are thought very unlikely to alter.

"+":
Some of the criteria have been fulfilled. Those criteria that have not been fulfilled or not adequately described are thought unlikely to alter the conclusions.

"-":
Few or no criteria fulfilled. The conclusions of the study are thought likely or very likely to alter.

The recommendations that were made as a result of the review were based on the Oxford Rating Scale.

Study Strengths / Weaknesses:

This was a thorough review of the literature that should be very helpful to clinicians in the treatment of patients with TrPs and MPS. It is especially helpful because it clears up much of the confusion that has resulted from clinical reviews which were not reliably based on published evidence.

Additional References:

  1. Hammer W. Functional soft tissue examination & treatment by manual methods. 3rd ed. Sudbury (Mass): Jones & Bartlett; 2007.
  2. Fernandez-de-la-Penas C et al. Manual therapies in myofascial trigger point treatment: A systematic review. J Bodywork Movement Ther 2005; 9: 27-34.
  3. The Scottish Intercollegiate Guidelines Network (SIGN). Notes on the use of Methodology Checklist 2: Randomised Controlled Trials from: http://www.sign.ac.uk/guidelines/fulltext/50/notes2.html February 26, 2009; Last modified February 26, 2008.