A new manual muscle test for assessing the entire trapezius muscle

Abstract

Manual muscle testing (MMT), the trapezius muscle is an important part of the examination in patients with upper extremity dysfunction or pain. Purpose: The purpose of this study was to assess the reliability and validity of a new MMT that assesses the entire trapezius muscle instead of the usual method of separating it into three different parts. The new trapezius MMT is similar to the serratus anterior muscle test; however, the testing is performed in the frontal versus sagittal plane. Methods: A convenience sample of 11 subjects was recruited with no known shoulder pathology. Surface electromyography electrodes were placed on the upper, middle, and lower trapezius fibers according to a previously validated method and MMTs for the three different trapezius muscle test positions were normalized against the new trapezius test position. Results: The new trapezius MMT showed very high maximal voluntary isometric contraction (MVIC; 160.80%) for the upper trapezius muscle, high for the middle trapezius muscle (59.23%), and high for the lower trapezius muscle (47.54%) when normalized against the MVICs for each individual trapezius muscle tests. Conclusions: A new MMT that assesses the whole trapezius in its role as an upward scapular rotator was found to be reliable and valid.