Anatomy, Shoulder and Upper Limb, Arm Supraspinatus Muscle

The supraspinatus muscle, the most superiorly located of the rotator cuff muscles, resides in the supraspinous fossa of the scapula, superior to the scapular spine. The tendon of the muscle extends laterally, passing under the acromion process and over the head of the humerus, blending into the glenohumeral joint capsule to insert onto the superior facet of the greater tuberosity of the humerus. In conjunction with the other three rotator cuff muscles, infraspinatus, teres minor, and subscapularis, the supraspinatus forms part of the dynamic stabilization for the glenohumeral joint.

These four muscles act in a coordinated fashion to stabilize the head of the humerus on the shallow glenoid fossa and promote the structural integrity of the joint. Along with its role as a stabilizer, the actions associated with supraspinatus are abduction of the humerus, which may contribute weakly to the lateral rotation of the humerus. As the most frequently torn rotator cuff muscle, the supraspinatus has been the subject of extensive research. Much is known, yet much is left to learn about this small but important muscle.