The rotator cuff helps keep your humerus, or upper arm bone, in your shoulder socket. These muscles also aid in overhead movements and rotational movements of the shoulder. The supraspinatus helps lift the arm out to the side. The infraspinatus rotates your arm outward and extends the shoulder. The teres minor muscle assists in shoulder rotation. And the subscapularis rotates the arm inward and moves the upper arm in.
Rotator cuff tears are common injuries that can occur to these muscles. It often happens due to overuse actions, such as lifting the arm above your head, or from direct impact. Treatment frequently includes physiotherapy and massage therapy.