Which muscles make up the rotator cuff?

The rotator cuff is a crucial group of muscles and tendons that stabilize the shoulder joint and allow for a wide range of arm movements. The muscles that specifically make up the rotator cuff are the supraspinatus, infraspinatus, teres minor, and subscapularis.

The supraspinatus is responsible for initiating the abduction of the arm, while the infraspinatus and teres minor primarily facilitate external rotation of the shoulder. The subscapularis, located on the anterior surface of the scapula, is key in internal rotation. Together, these muscles work synergistically to maintain the stability of the humeral head within the shallow glenoid cavity of the scapula during movement.

In contrast, the other choices list muscles that are either not involved in stabilizing the shoulder or do not contribute to the rotator cuff's specific functions. The deltoid and biceps brachii, for instance, are important muscles for shoulder movement but are not part of the rotator cuff. Thus, the correct identification of the rotator cuff muscles as the supraspinatus, infraspinatus, teres minor, and subscapularis is essential for understanding shoulder mechanics and