Supraspinatus

The supraspinatus muscle (Latin: musculus supraspinatus) is a flat triangular-shaped muscle of the upper limb. It stretches between the upper posterior aspect of the scapula and the proximal part of the humerus. As the supraspinatus acts at the shoulder joint, it is one of the muscles of the shoulder girdle. Besides providing movements of the arm, the supraspinatus muscle also stabilizes the shoulder joint. Together with the infraspinatus, teres minor and subscapularis, it belongs to the rotator cuff muscles.

Origin

The supraspinatus muscle originates from the supraspinous fossa located on the posterior surface of the scapula.

Insertion

The fibers of the supraspinatus pass laterally from the supraspinous fossa and insert on the greater tubercle of the humerus.

Action

The supraspinatus muscle provides abduction of the arm and stabilizes the glenohumeral (shoulder) joint.

Innervation

The supraspinatus is innervated by the suprascapular nerve that arises from the fifth and sixth cervical (C5, C6) nerve roots of the brachial plexus.

Blood supply

The arterial blood to the supraspinatus muscle is primarily supplied by the suprascapular artery - a branch of the thyrocervical trunk.