The greater and lesser tubercles are bony protrusions located on the humerus, which is the upper arm bone. These structures serve as important attachment points for muscles that are crucial for shoulder movement and stability.
The greater tubercle is the larger of the two tubercles and is situated on the lateral aspect of the humerus. It provides attachment for three of the rotator cuff muscles: the supraspinatus, infraspinatus, and teres minor. These muscles play vital roles in the stabilization and movement of the shoulder joint.
On the other hand, the lesser tubercle is smaller and located on the anterior aspect of the humerus. It serves as the attachment site for the subscapularis muscle, which is also part of the rotator cuff. The subscapularis is responsible for internal rotation of the arm.
In summary, the greater and lesser tubercles are essential for shoulder function, providing muscle attachments that facilitate a range of arm movements. Understanding their anatomy helps in diagnosing shoulder injuries and planning rehabilitation strategies.