There is a tremendous amount of stress placed on the shoulder during overhead throwing. “According to American Academy of Orthopedic Surgeons, there has been a fivefold increase in the number of serious shoulder and elbow injuries among youth baseball players since 2000.” 75% of college baseball injuries occur at the shoulder, and 50% of youth baseball players have complaints of shoulder or elbow pain.
The shoulder is very complex containing a ball and socket joint which allows for a significant amount of mobility. The head (ball) of the upper arm is four times larger than the socket (fossa) which is comparable to a golf ball sitting on a tee. This anatomical structure of the joint provides little stability making dynamic stabilizers vital to reduce the risk of injury. The dynamic stabilizers of the shoulder include the four rotator cuff muscles, biceps tendon, and scapula (shoulder blade) muscles.
Many throwing sports such as baseball not only require throwing at a high velocity but also at a high volume. A good conditioning program should improve the strength and endurance in the shoulder muscles to adequately meet the demands of the sport. Having good mobility and stability will allow the athlete the best opportunity to perform the movement with proper mechanics while placing the least amount of stress on the joint.