抄録
The delicate and harmonious function of the hand, controlled by the shoulder and elbow movements, enables us to do whatever we want. Particularly, the shoulder has great flexibility due to the glenohumeral joint, scapular and clavicular movements. The intended action cannot be performed until the subtle coordination of the muscles involved is achieved. The function of the muscles involved in the shoulder movements, especially the rotator cuff muscles, were analyzed using fine wire electrodes and an eight-channel penwriting galvanometer. Electromyogram and joint movements were synchronized and recorded on the same plane on a 16mm movie film or video tape. These film data were analyzed aualitatively with a film motion analyzer and a computer.
It was concluded that the rotator cuff muscles act as the main stabilizer of the glenohumeral joint. However, not all of the rotator cuff muscles are active during the mover or synergist actions in the shoulder movements.
