An Electromyographic Analysis of Normal Shoulder Muscular Co-ordination During Activities of Daily Living

INTRODUCTION The minimal bony constraint of the glenohumeral joint (GHJ) enables it to achieve a remarkable range of motion. Consequently, the stability of the joint must be maintained by the surrounding soft tissue structures; in particular the rotator cuff. The data available on normal shoulder function is sparse due to complex kinematics of the GHJ and technical difficulties in acquiring the data. Previous studies have been limited to planar shoulder movements which presents significant limitations when considering the function of the shoulder during activities of daily living. This study aims to define the activation patterns and coordination of muscles and muscle groups around the shoulder during activities similar to those of daily living. This will provide a better understanding of the normal shoulder function and hence, a basis for understanding the potential impact of shoulder pathology.