Final answer:
A lesser tuberosity avulsion is an injury where the lesser tuberosity, situated on the anterior side of the proximal humerus, is detached from the humerus, typically from sudden forceful muscle action. This injury contrasts with the greater tubercle, which is an attachment point for shoulder muscles on the lateral side of the proximal humerus. Treatment may require rest, immobilization, physical therapy, or surgery.
Step-by-step explanation:
A lesser tuberosity avulsion refers to an injury where the lesser tuberosity, a small bony prominence located on the anterior side of the proximal humerus, breaks away from the humerus bone. This can happen due to forceful muscle contraction, such as when the lateral rotator muscles of the shoulder are engaged during activities like throwing or lifting. This injury is often associated with shoulder dislocations.
The greater tubercle and the lesser tubercle are both important anatomical landmarks found on the proximal end of the humerus. The greater tubercle is an enlarged prominence located on the lateral side of the proximal humerus, which serves as an attachment point for several shoulder rotator cuff muscles. The lesser tuberosity, on the other hand, serves as the attachment point for the subscapularis muscle, one of the rotator cuff muscles responsible for medially rotating the arm.
Treatment for a lesser tuberosity avulsion often involves rest, immobilization, and physical therapy. In more severe cases, surgical intervention might be necessary to reattach the avulsed bone fragment back to its original position.