Muscles- Rotator Cuff

Subscapularis

A large triangular muscle which fills the subscapular fossa and inserts into the lesser tubercle of the humerus and the front of the capsule of the shoulder-joint.

Supraspinatus

A relatively small muscle of the upper back that runs from the supraspinatous fossa superior of the scapula (shoulder blade) to the greater tubercle of the humerus. It is one of the four rotator cuff muscles and also abducts the arm at the shoulder.

Teres Minor

A slim, narrow muscle within the rotator cuff, located in the shoulder. It is involved in the external rotation of the shoulder joint. The other muscles composing the rotator cuff are the supraspinatus, infraspinatus, and subscapularis. It connects the scapula to the humerus, along with the teres major and infraspinatus muscles, which lie on either side and overlap it.

Infraspinatus

muscle is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa. As one of the four muscles of the rotator cuff, the main function is to externally rotate the humerus and stabilize the shoulder joint.