The ability to sublux (partial dislocation) or fully dislocate the shoulder joint is possible for people with loose ligaments, a condition known as ligamentous laxity. Your son may have been born this way or he may have developed this condition over time with repetitive trauma. Swimmers and baseball players or volleyball players are affected most often.

It's best to avoid voluntarily popping the joint in and out. Over time the ligaments and other soft tissue structures holding the joint in place get stretched out. Pain can limit activities.

In rare cases, the individual may traumatically dislocate the shoulder. Surgery may be required if the joint capsule or the rim around the joint called the labrum are torn or ruptured.