The shoulder muscle labeled diagram typically shows the major muscles of the shoulder, including the deltoid, supraspinatus, infraspinatus, teres minor, and subscapularis muscles.

The deltoid muscle is a large triangular muscle that covers the shoulder joint and has three parts: the anterior, middle, and posterior fibers. The supraspinatus muscle is a small muscle located above the scapula that helps to lift the arm. The infraspinatus muscle is a larger muscle located below the scapula and is responsible for rotating the arm outward. The teres minor muscle is a small muscle located below the infraspinatus and also helps to rotate the arm outward. Finally, the subscapularis muscle is located on the underside of the scapula and is responsible for rotating the arm inward.

Together, these muscles work to stabilize and move the shoulder joint, allowing for a wide range of motion and function in the upper body.