 Hi, I'm Dr. Sushal Shantakumar. I'm a consultant shoulder surgeon practicing in Manipal Hospital's Bangalore. Shoulder is one of the most mobile yet the least stable joint in the body. So mobility comes at a price of stability. The many types of shoulder dislocation, so I will not go into that. The predominant ones are the anterior dislocation wherein the shoulder dislocates when you lift your arm or the shoulder over your head and try to reach something behind the back. So this is the commonest mode of shoulder dislocation.