Thirdly, a terrific compression occurs on the elbow as the arm reaches its fullest extension and the ball is released. Stresses that forcefully pull on the ligament attached to the inside of the elbow can lead to a sprain. Also, with repeated stress the injured muscle tendon unit that attaches to the armcan become partially or fully detached from the bony protrusion on the inside of the elbow. In more mature throwing athletes, partial detachment usually leads to formation of abnormal bone cells, which can be troublesome. Stresses on the lateral, or outside part of the elbow joint where the smaller forearm bone and the upper are bone meet occurs as the thrown object is released.
Sustained overuse can cause repetitive compression of bone against bone in the joint.
This can result in osteochondral fractures inside the joint, with small pieces of cartilage-covered bonebecoming detached. Fragments such as this cause joint pain, swelling and locking. A less common result of compression is formation of bone spurs. Obviously, these are very limiting injuries and require the attention of an orthopedic surgeon. The shoulder, in throwing and swimming sports, experiences similar stress and damage due to over use.