A shoulder dislocation occurs when the head of the humerus (upper arm bone) pops out of the shallow shoulder socket of the scapula (called the glenoid). This can happen when a strong force pulls the shoulder upward or outward, or from an extreme external rotation of the humerus.
Glenohumeral dislocations are generally classified by the direction of dislocation of the humerus.
Dislocation can be full or partial:
- Partial dislocation (also called subluxation)—the head of the humerus slips out of the socket momentarily and then snaps back into place
- Full dislocation—the head of the humerus comes completely out of the socket
Shoulder dislocations can also be associated with fractures—one can have a fracture and dislocation at the same time. Nerves and blood vessels can sometimes be injured with a severe shoulder dislocation, requiring immediate medical attention.
Shoulder dislocation can be caused by:
- Falling on an outstretched arm
- A direct blow to the shoulder area, such as in automobile accident
- Forceful throwing, lifting, or hitting
- Force applied to an outstretched arm, such as in a football tackle
Factors that may increase your chance of a shoulder dislocation include:
- Pain, often severe
- Instability and weakness in the shoulder area
- Inability to move the shoulder
- Shoulder contour appears abnormal
- Numbness and tingling around the shoulder or in the arm or fingers
The doctor will ask about your symptoms and how the injury occurred, and will examine the injured area. Diagnosis is also based on the physical exam of your shoulder area. The doctor may do an x-ray to rule out a related fracture or damaged surrounding soft tissue and to see which direction the shoulder is dislocated.
Seek medical care right away. Do not try to put your shoulder bones back into place. If you wait for treatment, you could cause permanent damage.
The doctor will move the head of the humerus back into the shoulder joint socket by applying traction to your arm. You will be given pain medication before this procedure begins. After the reduction, you will need to wear a sling or a device called a shoulder immobilizer to keep the shoulder from moving. The shoulder is generally immobilized for about 4 weeks, and full recovery takes several months. Surgery is rarely needed for a first time dislocation. It is often needed for a shoulder that dislocates repeatedly.
Rest and Recovery
It is important to rest your shoulder and not put any strain on the joint area. This will require a reduction in activities while your shoulder heals. However, complete rest is rarely required. Ice and elevating your arm at rest may also be advised to help with discomfort and swelling. Ask your doctor when you can switch from ice to heat.
As you recover, you may be referred to physical therapy or rehabilitation to start range-of-motion and strengthening exercises. Do not return to activities or sports until your doctor gives you permission to do so.
Your doctor may advise nonsteroidal anti-inflammatory drugs (NSAIDs) to help relieve inflammation and pain.
To help reduce your chance of a shoulder dislocation:
- Do exercises to strengthen the muscles around your shoulder
- Wear proper safety equipment and padding for protection in sports
- Avoid falls
- Reviewer: Michael Woods, MD
- Review Date: 12/2014 -
- Update Date: 12/20/2014 -