What muscle is inserted at the greater tubercle of the humerus?

The muscle that is inserted at the greater tubercle of the humerus is the infraspinatus. This muscle is one of the rotator cuff muscles and plays a crucial role in stabilizing the shoulder joint as well as facilitating the external rotation of the arm. Its attachment at the greater tubercle allows the infraspinatus to effectively contribute to the movement and stabilization required during various arm activities.

The greater tubercle itself serves as a prominent bony landmark on the humerus, providing a strategic site for these important muscles that govern shoulder movement. The design of the shoulder joint—with its extensive range of motion—makes the role of the infraspinatus essential for both dynamic and stability functions in the upper extremity. In contrast, the other muscles listed either perform different functions or insert at different locations on the humerus, making the infraspinatus the correct answer to the query about which muscle is specifically associated with the greater tubercle.