Shoulder Injuries in the Throwing Athlete
Shoulder injuries in baseball players are usually associated with pitching. While this overhand throwing activity can produce great speed and distance for the ball, when performed repeatedly, it can place a lot of stress on the shoulder.
The shoulder is a shallow ball and socket joint, formed by the bone of the upper arm (humerus), which articulates with the shoulder blade in a cavity called the glenoid fossa. The joint relies a great deal on surrounding soft-tissue structures such as tendons, ligaments and muscles (rotator cuff muscles) to maintain smooth motion and stability. The glenoid cavity is surrounded by a raised ridge of cartilage called the labrum that deepens the cavity and a ligamentous structure called the shoulder capsule centers the humerus in the cavity. The biceps muscle, shoulder blade muscles, as well as a group of muscle tendon units called the rotator cuff all work together to stabilize the shoulder.
Pitching requires a well-balanced kinetic chain from the feet through the core and finally to ball release from the hand. While pitching, the arm is externally rotated and then rapidly accelerated forward to generate speed. This action stresses the surrounding ligaments and tendons. These stresses as well as any imbalances in the kinetic chain can lead to injuries, causing pain and inflammation. Common injuries include:
- Tears of the labrum
- Tendonitis (inflammation of the tendons) and tears of the rotator cuff
- Tendonitis and tears of the biceps tendon
- Impingement of the rotator cuff tendons between the humeral head and glenoid
- Partial dislocation of the joint (instability)
Pain and instability of the shoulder can result in reduced throwing velocity and accuracy.
Your physician will assess your shoulder injury by reviewing your pain and the movements that produces it and performing a thorough physical examination of your shoulder and entire kinetic chain. Imaging studies such as X-rays and MRIs may be ordered.
Most shoulder injuries involve soft tissue structures which can be treated by a period of rest, ice application, medication, and physical therapy to restore a balanced kinetic chain and to stretch and strengthen the muscles and ligaments of the shoulder, improving and maintaining range of motion. A change in throwing technique may be suggested to reduce stress on the injured shoulder. If pain persists, arthroscopic surgery may be considered to repair labrum tears debride partial rotator cuff tears. Following surgical repair, return to full-speed throwing may take up to six months.