Any type of dislocation causes pain and instability in your shoulder. Your muscles may have spasms from the disruption. This can make it hurt more. Other symptoms can include swelling, numbness, weakness and bruising. Sometimes dislocation may tear ligaments or tendons in your shoulder. Once in awhile, a dislocation may damage your nerves.
Your shoulder joint can dislocate forward, backward or downward. A common type of shoulder dislocation is when your shoulder slips forward (anterior instability). This means your upper arm bone moved forward and down out of its joint. It may happen when you put your arm in a throwing position.