The shoulder is a complex joint that allows for the most range of motion of any joint in the human body. In order to accomplish this goal, the shoulder must remain stable throughout its' entire range of motion. The shoulder is comprised of a ball (the humeral head) and a socket (the glenoid). A complex array of ligaments and muscles help to keep the ball centered in the socket through our normal use of the arm. When a shoulder is unstable, the ball can become dislodged from the socket and dislocate. This can happen from an acute traumatic event such as a rough tackle in football, or it can arise from multiple small events ("microtrauma") from repetitive overuse (pitching in baseball, for instance).
Traumatic shoulder instability is most often found in young athletes and the young adult population. The younger and more active an individual is when the first dislocation occurs, the more likely there is to be a recurrence of instability. The older a patient is when they experience their first dislocation, the less likely they are to experience a recurrence of their instability. Treatment strategies are tailored to the age and activity level of the patient and are made on a case by case basis.