Research Review: Electromyographic analysis of infraspinatus and scapular muscles during external rotation with different weight loads and positions.
By David Boettcher MSc, BA, NASM CPT, PES& CES & NPTI
Edited by Brent Brookbush DPT, PT, COMT, MS, PES, CES, CSCS, ACSM H/FS
Sasaki, S., Kenmoku, T., Otera, A., Miyajima, G., Nagura, N...Takahira, N. (2017). Electromyographic analysis of infraspinatus and scapular muscles during external rotation with different weight loads and positions. Journal of orthopaedic science, 28(1), 154-158 - ARTICLE
Resisted external rotation is commonly used as a strengthening exercise for the posterior rotator cuff musculature (1,2). Lighter loads are often recommended with the intent of optimizing form and reducing recruitment of synergistic muscles. This 2017 study by Japanese researchers, compared the electromyographic (EMG) activity of the infraspinatus, posterior deltoid, upper trapezius and bicep brachii during seated and supine resisted external rotation with varying loads. The study findings suggest seated external rotation using a higher load, with 0º of shoulder abduction and 90º of elbow flexion, may result in the greatest infraspinatus activity.
Musculature surrounding the shoulder
|Study Design||Observational/Comparative study|
|Level of Evidence||III - Evidence from non-experimental descriptive studies, such as comparative studies, correlation studies, and case-control studies|