which muscles are part of the rotator cuff
Rotator cuff In anatomy, the rotator cuff [1]) is a group of muscles and their tendons that act to stabilize the shoulder. Of the seven scapulohumeral muscles, four make up the rotator cuff. The four muscles are the supraspinatus muscle, the infraspinatus muscle, teres minor muscle, and the subscapularis muscle.
Biceps The biceps, also biceps brachii is a two-headed muscle that lies on the upper arm between the shoulder and the elbow. Both heads arise on the scapula and join to form a single muscle belly which is attached to the upper forearm. While the biceps crosses both the shoulder and elbow joints, its main function is at the elbow where it flexes the forearm and supinates the forearm. Both these movements are used when opening a bottle with a corkscrew: first biceps unscrews the cork (supination), then it pulls the cork out (flexion).[2]