Electromyography activity of selected muscles of shoulder complex during functional movements in a closed chain exercises among female bodybuilders with shoulder impingement syndrome

Shoulder impingement syndrome is common in bodybuilding athletes due to performing various overhead exercises. The purpose of this study was to determine the electromyography activity of selected muscles of shoulder complex during some functional movements among female bodybuilders with shoulder impingement syndrome. Ten healthy female bodybuilders and 10 bodybuilders with symptoms of shoulder impingement syndrome participated in this semi-experimental study. The average and maximum electromyographic activity of the anterior deltoid, pectoralis major, serratus anterior, posterior deltoid, and upper and lower part of the trapezius muscles were recorded in three exercises namely, Australian chain-up, push-up and parallel bar dip. Independent t-test and analysis of variance with repeated measures were employed for statistical analyses (p<0.05). The average and maximum activity of the selected muscles was higher in the parallel bar dip movement than those in other movements in both groups. Muscles activity in push-up movement also were heigh compared to reverse push-up movement. Subjects with shoulder impingement syndrome showed a low co-contraction during push-up movement in comparison with two other movements. Directed co-contraction was also lower in the Australian chain-up movement than in the other two movements. Female bodybuilders with shoulder impingement syndrome had greater electromyographic activity in the anterior muscles of the pectoralis major and anterior deltoid when performing three closed-chain movements namely, Australian chain-up, push-up and parallel bar dip, than healthy athletes. This action may create a compensatory mechanism for other muscles around the shoulder joint, causing a change in the pattern of muscle activity.