Shoulder instability/dislocation
The main joint in the shoulder is a ball and socket joint, which can become unstable or dislocate for a number of reasons. Physiotherapy is often recommended to retrain the muscles and soft tissues around the shoulder joint to maximise its stability.
What is shoulder instability/dislocation?
The shoulder is comprised of a number of joints. The main joint in the shoulder is a ball and socket joint called the glenohumeral joint. The glenohumeral joint is a very mobile joint to enable us to use our hand in a variety of functional ways, and relies on the muscles, ligaments and cartilage for its stability. The socket is fairly shallow in which the ball sits in. Lining the socket is a layer of cartilage, which deepens the socket and also provides a bumper to help keep the ball within the socket as we move our arm.
Sometimes people will experience subluxations, which is where the ball slips out of the socket without dislocating completely. A shoulder dislocation is where the ball completely loses contact with the socket, and sometimes it will pop back in itself, or sometimes it needs putting back by someone who has been specially trained in relocation techniques. Sometimes a dislocation can cause damage to parts of the joint such as the muscles, ligaments, cartilage or bones themselves, resulting in your shoulder continuing to feel unstable or like you don’t have confidence in it, or causing you to experience repeated dislocations.
Who does it affect?
The glenohumeral joint can be unstable for a variety of reasons, such as following a sporting injury or a fall resulting in a dislocation. It can also be unstable due to issues with the surrounding muscles, cartilage and ligaments not being tight or responsive enough to keep the ball in the socket. Shoulder instability can be quite common in early adulthood, with or without any previous shoulder injuries.