16-1 Reliability and Validity of Manual Muscle Testing: A Systematic Literature Review

 Reliability and Validity of Manual Muscle Testing:  A Systematic Literature Review / Igal Kazap

Abstract

Background: Manual muscle testing (MMT) is one of the accepted tests for assessing muscle strength in the clinic. It is a simple and inexpensive test, and does not require the use of equipment. Despite the widespread use of this test, there is not enough information about its validity and reliability.

Objective: To review the studies published in the past ten years that assessed the reliability and validity of the MMT.

Methods: PubMed, NARIC, CIRRIE, EBSCO, Google Scholar, EM consult, Cochrane Library, Web of Science & Medscape CME were searched. Inclusion criteria for the study were articles that deal with the reliability and/or validity of the MMT, used the Medical Research Council (MRC) Scale, were published in English and could be obtained in full text. All studies included in the study were assessed using the "Critical appraisal tool for validity and reliability studies of objective clinical tools". The validity studies were evaluated using also the "Levels of Evidence for Primary Research Question".

Results: The initial search found over 300 studies; after reading their titles and abstracts, only nine articles that dealt with the reliability and/or validity of the MMT seemed relevant. Of these, eight dealt with reliability; one dealt with structural validity; and two dealt with both reliability and validity. Most of the articles seemed to be of low or moderate quality, while only one study was of high quality.

Discussion and Conclusions: The assessment of the studies reviewed shows that it is possible to use the method of MMT to evaluate levels of muscle strength in certain populations; however, additional studies employing a high quality methodology are needed to establish the reliability and validity of the MMT method for distinguishing different levels of muscle strength.

Keywords: muscle testing; manual muscle testing; reliability; validity; systematic review.