What is a dislocated shoulder?

What is a dislocated shoulder?

A shoulder dislocation occurs when the round ball at the top of the upper arm bone, or humerus, leaves the socket in the shoulder blade, or scapula. That means the ball and socket bones of the shoulder are separated, with the ball of the humerus out of position.

Tissues that hold the bones together – including muscles, tendons that connect muscles to bones and ligaments that join the shoulder bone to the shoulder blade – are also sometimes injured. In addition, tearing of cartilage, a rubbery tissue that covers and protects the ends of bones, is possible.

A partially dislocated shoulder, or shoulder subluxation, means that only part of the upper arm bone is out of socket.