Which of the following is NOT one of the four rotator cuff muscles?

The deltoid is not considered one of the four rotator cuff muscles. The rotator cuff is made up of four specific muscles: the supraspinatus, infraspinatus, teres minor, and subscapularis. These muscles work together to stabilize the shoulder joint and enable a range of movements.

The deltoid, on the other hand, is a large muscle that forms the rounded contour of the shoulder. It is primarily responsible for arm abduction, flexion, and extension, but it does not play a direct role in stabilizing the shoulder joint like the rotator cuff muscles do. By understanding the distinct functions and anatomical positions of these muscles, it becomes clear why the deltoid is not part of the rotator cuff group.