(dislocated shoulder) Your shoulder joint is made up of three bones: your collarbone, your shoulder blade, and your upper arm bone. The top of your upper arm bone is shaped like a ball. This ball fits into a cuplike socket in your shoulder blade. A shoulder dislocation is an injury that happens when the ball pops out of your socket. A dislocation may be partial, where the ball is only partially out of the socket. It can also be a full dislocation, where the ball is completely out of the socket. Your shoulders are the most movable joints in your body. They are also the most commonly dislocated joints. The most common causes of shoulder dislocations are: Sports injuries; Accidents, including traffic accidents; Falling on your shoulder or outstretched arm; Seizures and electric shocks, which can cause muscle contractions that pull the arm out of place. A dislocated shoulder can happen to anyone, but they are more common in young men, who are more often involved in sports and other physical activities. Older adults, especially women, are also at higher risk because they are more likely to fall. The symptoms of a dislocated shoulder include: Severe shoulder pain; Swelling and bruising of your shoulder or upper arm; Numbness and/or weakness in your arm, neck, hand, or fingers; Trouble moving your arm; Your arm seems to be out of place; Muscle spasms in your shoulder. If you are having these symptoms, get medical treatment right away. To make a diagnosis, your health care provider will take a medical history and examine your shoulder. Your provider may also ask you to get an x-ray to confirm the diagnosis. The treatment for dislocated shoulder usually involves three steps: The first step is a closed reduction, a procedure in which your health care provider puts the ball of your upper arm back into the socket. You may first get medicine to relieve the pain and relax your shoulder muscles. Once the joint is back in place, the severe pain should end.; The second step is wearing a sling or other device to keep your shoulder in place. You will wear it for a few days to several weeks.; The third step is rehabilitation, once the pain and swelling have improved. You will do exercises to improve your range of motion and strengthen your muscles. You may need surgery if you injure the tissues or nerves around the shoulder or if you get repeated dislocations. A dislocation can make your shoulder unstable. When that happens, it takes less force to dislocate it. This means that there is a higher risk of it happening again. Your health care provider may ask you to continue doing some exercises to prevent another dislocation.

A dislocation of the shoulder joint.

A displacement or misalignment of the humerus with respect to the other bones of the should joint. Note that a subluxation is a partial dislocation.

Displacement of the HUMERUS from the SCAPULA.

In shoulder (glenohumeral) dislocations, the humeral head separates from the glenoid fossa; displacement is usually anterior. Shoulder dislocations account for about half of major joint dislocations.

Shoulder dislocations may occur from a traumatic injury or from loose capsular ligaments. Different conditions may affect the stabilizing structures of the shoulder and, thus, negatively affect patients with shoulder dislocations.

A dislocated shoulder is an injury in which your upper arm bone pops out of the cup-shaped socket that's part of your shoulder blade. The shoulder is the body's most mobile joint, which makes it susceptible to dislocation.