Shoulder electromyography measurements during activities of daily living and routine rehabilitation exercises
STUDY DESIGN: Controlled laboratory study. BACKGROUND: The activity of the rotator cuff muscles has not previously been measured with indwelling electromyography (EMG) comparing ambulation and other movements. Knowledge of the relative contribution of these muscles during various tasks may help to guide rehabilitation progression. OBJECTIVE: To measure activity of the rotator cuff muscles and other shoulder muscles during normal ambulation, shirt and sling donning and doffing, and rehabilitation tasks commonly performed after rotator cuff surgery. METHODS: In 28 volunteers (15 men, 13 women; mean age, 32.2 years), indwelling EMG activity was measured in the supraspinatus, infraspinatus, teres minor, and subscapularis muscles during various tasks; and surface EMG activity was measured in the middle deltoid, biceps, and upper trapezius muscles. RESULTS: Using median EMG activity, in general, donning and doffing a shirt or sling recruited the rotator cuff muscles more than the other 7 tasks tested. Self-ranging motion using pulleys, especially in the scapular plane, was also consistently associated with greater recruitment of the shoulder muscles. Pendulum exercises, passive range of motion by a physical therapist, and self-ranging motion with a dowel recruited the shoulder muscles to a lesser extent. CONCLUSION: Our results demonstrate that rehabilitation tasks such as pendulum exercises, passive range of motion by a physical therapist, and self-ranging motion with a dowel show low EMG activity, whereas pulleys in the sagial plane and scapular plane show greater activity. Scapular plane activity was consistently higher than sagial plane activity. Of all the tasks assessed, ambulation without a sling and donning and doffing a sling and a shirt consistently showed the highest activity.
Journal of Orthopaedic and Sports Physical Therapy
Gurney, A., Mermier, C., Laplante, M., Majumdar, A., O'Neill, K., Shewman, T., & Gurney, J. (2016). Shoulder electromyography measurements during activities of daily living and routine rehabilitation exercises. Journal of Orthopaedic and Sports Physical Therapy, 46 (5), 375-383. https://doi.org/10.2519/jospt.2016.6090