J Manipulative Physiol Ther. 2009 (Jan); 32 (1): 1424 ~ FULL TEXT
Howard Vernon, DC, PhD, and Michael Schneider, DC
Canadian Memorial Chiropractic College,
OBJECTIVES: Myofascial pain syndrome (MPS) and myofascial trigger points (MTrPs) are important aspects of musculoskeletal medicine, including chiropractic. The purpose of this study was to review the most commonly used treatment procedures in chiropractic for MPS and MTrPs.
METHODS: The Scientific Commission of the Council on Chiropractic Guidelines and Practice Parameters (CCGPP) was charged with developing literature syntheses, organized by anatomical region, to evaluate and report on the evidence base for chiropractic care. This article is the outcome of this charge. As part of the CCGPP process, preliminary drafts of these articles were posted on the CCGPP Web site www.ccgpp.org (2006-8) to allow for an open process and the broadest possible mechanism for stakeholder input. PubMed, Excerpta Medica Database, Cumulative Index to Nursing and Allied Health Literature, and databases for systematic reviews and clinical guidelines were searched. Separate searches were conducted for (1) manual palpation and algometry, (2) chiropractic and other manual therapies, and (3) other conservative and complementary/alternative therapies. Studies were screened for relevance and rated using the Oxford Scale and Scottish Intercollegiate Guidelines Network rating system.
RESULTS: A total of 112 articles were identified. Review of these articles resulted in the following recommendations regarding treatment: Moderately strong evidence supports manipulation and ischemic pressure for immediate pain relief at MTrPs, but only limited evidence exists for long-term pain relief at MTrPs. Evidence supports laser therapy (strong), transcutaneous electrical nerve stimulation, acupuncture, and magnet therapy (all moderate) for MTrPs and MPS, although the duration of relief varies among therapies. Limited evidence supports electrical muscle stimulation, high-voltage galvanic stimulation, interferential current, and frequency modulated neural stimulation in the treatment of MTrPs and MPS. Evidence is weak for ultrasound therapy.
CONCLUSIONS: Manual-type therapies and some physiologic therapeutic modalities have acceptable evidentiary support in the treatment of MPS and TrPs.
From the Full-Text Article:
Ever since the seminal work of Travell and Rinzler  in 1952, the role of myofascial trigger points (TrPs) in myofascial pain syndrome (MPS) has become an accepted part of musculoskeletal clinical practice. Along with Simons,  Travell first identified the importance of myofascial pain and its localization in what they termed trigger points, providing the first classification of diagnostic criteria for TrPs. They also provided detailed maps of the pain referral patterns from TrPs in all the muscles of the body. Myofascial pain syndrome is currently thought to be the leading diagnosis among pain management specialists  and the leading diagnosis in pain patients reporting to general practitioners. 
Interest in myofascial tenderness extends throughout the history of chiropractic. It might be said that local paraspinal tenderness, as part of the manifestations of the subluxation, was a central feature of chiropractic thinking from its inception. Arguably, the work of Ray Nimmo  represents the earliest and perhaps still most established thinking on this topic among chiropractors. Cohen and Gibbons  describe his work as a conceptual leap from moving bones to working with muscles that move bones. Schneider [9, 10] has provided a collection and review of all of Nimmo's works. Nimmo's explanations in the 1950s of the pathophysiology of TrPs are still regarded as accurate and highly sophisticated.
Other chiropractic authors who have written on this topic include Schneider,  Perle, [13, 14] Hains, [15, 16] and Hammer,  whose seminal textbook is now in its third printing. There are also numerous case reports and technical reports relating to various soft tissue techniques in chiropractic. In the field of MPS, chiropractic is generally regarded as one of the complementary and alternative medical (CAM) therapies. The CAM therapies are quite commonly used in the treatment of myofascial pain and TrPs,  and there is considerable overlap between chiropractic approaches and CAM therapies in this field.
The published evidence for the treatment of MPS and TrPs by common chiropractic treatments has been reviewed. Although publications ranging from systematic reviews and clinical trials to clinical reviews were included in the review, the evidence ratings were developed only on the basis of the clinical trial evidence. Manual-type therapies and some physiologic therapeutic modalities have acceptable evidentiary support in the treatment of MPS and TrPs (Table 10).
There is evidence that manual therapies are useful in short-term relief of TrP pain.
There is evidence that laser and acupuncture are useful in the short- and long-term relief of MPS.
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