earticle

영어

The purpose of this study was to investigate the effect of shoulder rotation and scapular position on muscle activity of the anterior deltoid (AD), middle deltoid (MD), posterior deltoid (PD), and upper trapezius (UT) during lateral raise (LR) in healthy adults. Five healthy individuals were recruited to participate in the study. The muscle activities of UT, AD, MD, and PD were measured using surface electromyography during LR. The muscle activity of UT, AD, MD, and PD was measured under four conditions: 1) shoulder external rotation with scapular neutral, 2) shoulder internal rotation with scapular neutral, 3) shoulder external rotation with scapular depression and retraction, and 4) shoulder internal rotation with scapular depression and retraction, all in the sitting position. The results showed that muscle activity of MD and PD increased with internal rotation of the shoulder, whereas muscle activity of UT decreased with external rotation. Additionally, with respect to changes in scapular position, the muscle activity was high in MD with a neutral position. Therefore, when performing shoulder LR exercise and weight training in a clinical setting, LR exercise with external rotation of the shoulder should be considered to reduce the overactivity of UT and to appropriately create subacromial space.