Which rotator cuff muscle does NOT insert into the greater tuberosity of the humerus?

The subscapularis muscle is the rotator cuff muscle that does not insert into the greater tuberosity of the humerus. Instead, it inserts into the lesser tuberosity of the humerus. This is an important distinction because the insertion points are anatomically significant and influence the functions of these muscles in shoulder movement and stability.

The supraspinatus, infraspinatus, and teres minor all insert into the greater tuberosity, which is a critical aspect of their role in facilitating arm movement and maintaining the integrity of the shoulder joint. The specific insertion of the subscapularis into the lesser tuberosity allows it to play a key role in internal rotation of the arm, setting it apart from the other rotator cuff muscles.

Understanding these differences is essential for understanding shoulder anatomy and the specific roles each muscle plays in abduction, external rotation, and internal rotation of the arm.