Date of Award
Master of Physical Therapy (MPT)
Susan H.N. Jeno
Electromyography; Muscles -- physiology
Many people use repeated overhead movements in their occupations or recreational activities. Literature has shown that this repeated overhead activity greatly contributes to the incidence of shoulder pathologies such as impingement syndrome. The purpose of this study was to establish whether the lower trapezius was more successfully recruited in the traditional muscle testing position of 145° of shoulder abduction or a modified position consisting of shoulder external rotation while in 80° of shoulder abduction and 90° of elbow flexion.
Forty-one subjects between the ages of 21 and 45 voluntarily participated in this study. One subject was excluded due to exceeding the 18- to 45-year-old age limit. EMG data were recorded and collected from the right lower trapezius of each subject while they completed 10 repetitions of each exercise in the traditional position with weight, the traditional position without weight, the modified position with weight, and the modified position without weight. The exercises were performed in a random order for each subject.
Results of this study showed a significant difference in total and average lower trapezius muscle activity between the traditional position without weight and the traditional and modified positions with weight. The traditional and modified positions with weight demonstrated a greater level of EMG activity than the traditional position without weight. No significant difference was shown for total or average lower trapezius muscle activity between the traditional position without weight and the modified position without weight or between the traditional position with weight and the modified position with weight.
The results indicated that exercise in the modified position with weight effectively recruits the lower trapezius at a higher amount than traditional positions and allows the patient to exercise the lower trapezius muscle in a position that is potentially less detrimental to the shoulder complex.
Doyle, Keri M.; McDonald, Molly E.; Partlow, Heather M.; and Paur, Eric R., "An Electromyographic Study of Lower Trapezius Muscle Activity during the Traditional Muscle Testing Position and a Modified Position" (2004). Physical Therapy Scholarly Projects. 121.