抄録
Clinically, strengthening exercises for scapular abductor muscles such as serratus anterior is usually prescribed for patients with scapular winging. However, the effect of such exercises on shoulder function is still unclear. The purpose of this study was to examine the changes of muscle strength on the shoulder joint after exercise for scapular abductor muscles. Thirty-six healthy male subjects participated in this study. All subjects were randomly assigned to either the exercise group (EX group) or control group (CO group). Initially, the muscle strengths of scapular protraction (PR), shoulder flexion (FL), abduction (AB), external rotation (ER), and internal rotation (IR) were measured in both groups. The EX group was instructed to perform the modified "elbow push up plus". The CO group did not perform any exercise. The muscle strengths were measured again after the training period. The paired t-test was used to compare the muscle strengths between before and after the training period. The muscle strengths of scapular PR, shoulder FL, AB and IR were significantly increased in the EX group (p<0.05). On the other hand, no significant increase was found in the CO group. Since the movement of shoulder FL, AB and IR involve scapular posterior tilt, upward rotation, and protraction movement, respectively, the increase of scapular abduction strength might have caused the increase in muscle strengths of shoulder FL, AB and IR. The muscle strength of the shoulder complex may depend on the function of the scapulothoracic joint.
