Rotator cuff is formed by all, EXCEPT:

Rotator cuff of the shoulder is a fibrous sheath formed by the flattened tendons which blend with the capsule of the shoulder joint and strengthen it. The muscle which form the cuff arise from the scapula and are inseed into the lesser or greater tubercle of the humerus. These muscle are the subscapularis, supraspinatus, infraspinatus and teres minor. Their tendon, while crossing the shoulder joint, become flattened and blends with each other on one hand, and with the capsule of the joint on the other hand, before reaching their points of inseion.Also know:The cuff gives strength to the capsule of the shoulder all around except inferiorly which explains why the dislocation of the humerus occur most commonly in downward direction. Ref: CSDT 11/e, Page 1132, 1197 ; BDC 4/e, Vol. I, Page 78-79.