Manual Muscle Testing (MMT) is a tool used by over a dozen methods/therapies. Since MMT is important to the decision making process for so many modalities, it stands to reason that understanding the efficacy and accuracy of MMT would be of great interest. It is perfectly understandable that a professional who uses MMT in their practice would look for evidence that supports the accuracy and efficacy of MMT. This is a perfectly fine thing to do, but do not confuse it with science. Scientists are keenly interested in reporting and exploring all data related to the subject even if some or most of the data refutes the initial understanding.
Scott C. Cuthbert and George J. Goodheart, Jr. addressed the issue of MMT efficacy and accuracy in their review paper entitled, “On the reliability and validity of manual muscle testing: a literature review," (Chiropractic & Osteopathy, 15(1), 4). A superficial read of this paper may lead one to believe that Cuthbert and Goodheart found evidence to support their assertion that "With regard to analysis there is evidence for good reliability and validity in the use of MMT for patients with neuromusculoskeletal dysfunction. The observational cohort studies demonstrated good external and internal validity, and the 12 randomized controlled trials (RCTs) that were reviewed show that MMT findings were not dependent upon examiner bias.” However, a closer reading of Cuthbert and Goodheart's review reveals several rational and empirical issues. Some of these issues were published less than a year later, by the same journal! The commentary by Haas, Cooperstein, and Peterson, refuted Cuthbert and Goodheart’s review. Here is some of what they had to say:
“... the review contains critical errors in the search methods, inclusion criteria, quality assessment, validity definitions, study interpretation, literature synthesis, generalizability of study findings, and conclusion formulation that merit a reconsideration of the authors' findings. Most importantly, a misunderstanding of the review could easily arise because the authors did not distinguish the general use of muscle strength testing from the specific applications that distinguish the Applied Kinesiology (AK) chiropractic technique. The article makes the fundamental error of implying that the reliability and validity of manual muscle testing lends some degree of credibility to the unique diagnostic procedures of AK.” (Disentangling manual muscle testing and Applied Kinesiology: Critique and reinterpretation of a literature review. Chiropractic & Osteopathy, 15(1), 11.)
I encourage you to read the full commentary. It is a great example of how rational discourse brings greater clarity to a subject. Disagreement is fine. Being wrong is fine. Both are necessary. The question is, once you have greater insight, are you willing, courageous, and inventive enough to alter your behavior, actions, and decisions? Or will you do what is easier and more familiar even if it is riskier and less advantageous?
“Mastery is great, but even that is not enough. You have to be able to change course without a bead of sweat, or remorse.” Tom Peters
A special thank you to the MSC for the assistance in researching the material for this piece.