Age-related Differences in Shoulder Dynamic and Isometric Contractions

SEMG was used to measure the amplitude and onset of five shoulder muscle electrical signal, performing glenohumeral abduction. In this movement, the middle deltoid muscle was selected because it is a main motor. The infraspinatus muscle represented the rotator cuff muscle group. The middle deltoid muscle was selected as the representative of shoulder abduction because it is a main motor in this movement. The trapezius muscle and the serratus anterior muscle were chosen as representative established of the ascending scapular rotator muscles.