The shoulder is the most commonly dislocated joint of the body. According to the Mayo Clinic, a dislocated shoulder is an injury in which the upper arm bone pops out of the shoulder socket. This can cause a visibly deformed shoulder, pain, swelling, bruising and an inability to move the shoulder joint, states the American Academy of Orthopedic Surgeons (AAOS).
Contact Sports
The Mayo Clinic states that a shoulder dislocation is a common injury in contact sports such as football, hockey, rugby and basketball; skiers, gymnasts and volleyball players are at a high risk as well. Dislocations occur due to hard blows to the upper arm bones, which can knock them out of the shoulder sockets.
Car Accidents
Other traumatic events, such as a car accident, may cause a shoulder dislocation. Although seatbelts may prevent serious injury, high-speed car accidents may still transmit enough force to the upper arm bone to cause a dislocation.
Falls
Falls are also common causes of shoulder injuries. A fall from a ladder, or from tripping over a crack or unseen object, may cause a shoulder dislocation. Specifically, a shoulder is more prone to dislocating when a person falls on an outstretched hand. The force of the fall is transmitted to the upper arm bone, which may cause it to dislocate.
