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Shoulder Dislocation

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The shoulder tends to be the most mobile of all joints in the body. It is capable of turning in any number of different directions. Due to this advantage, it makes the shoulder one of the easiest joints to dislocate. Partial dislocation (or subluxation) means that the head of the humerus is only partially out of the socket. If the joint is completely dislocated, it means that it is completely out of the socket. Both complete and partial dislocations can cause unsteadiness and pain in the shoulder.

Why Do Shoulder Dislocations Occur?

Shoulder dislocations always happen due to trauma. The force applied to the arm in a particular direction is enough to push the arm bone away from the socket. This force is typically significant.

  • Trauma in sport – usually in sports like rugby, football, hockey, and American football. A player tackles the other player who either falls badly or has the arm wrenched causing a dislocation.
  • Blunt trauma – sustaining a strong impact directly to the shoulder joint (usually again in sport) can dislocate the shoulder.
  • Falling – more common in the elderly, a dislocation can occur from a fall to the side of the shoulder, the tip of the shoulder, or falling on an outstretched arm.
  • Snow sports – a very common way to dislocate the shoulder. Snowboarders and skiers are prone to falling and can dislocate the shoulder.
  • Recurring dislocations – often do not involve any trauma. Once you have dislocated the shoulder once, the shoulder is looser and can be unstable. This instability can mean the shoulder just pops out with smaller movements at the wrong angle. Also during sleep, the shoulder can pop out after turning in bed.

Shoulder Dislocation Anatomy

The shoulder is made up of several joints, but the main joint is the glenohumeral joint which is the ball and socket joint. This is formed of the glenoid (the socket) and the head of the humerus (the ball). Around the edge of the socket is a rim which is called the labrum. The labrum helps to hold the ball in place, and makes the socket slightly deeper. This helps to further reduce the likelihood of shoulder dislocation.

When the shoulder subluxes, the head of the humerus almost comes out of the glenoid cavity (the socket) but then within a few seconds pops back into place.

When the shoulder dislocates, the head of the humerus comes out of the glenoid cavity and remains outside of the joint. This causes potential damage to a number of associated structures including the labrum (the labrum/rim is torn as the ball comes out), rotator cuff tendons that attach to the joint, ligaments around the joint, and the joint capsule itself.

shoulder dislocation bone structure image

How to Treat a Shoulder Dislocation

1. Closed Reduction

The ball of the upper arm will be “placed” back into the joint socket, which is known as a closed reduction. Severe pain will stop once the shoulder has returned to position. In reality, the shoulder is hard to get back in especially the first time it has been dislocated. So a number of methods are used. First, the shoulder may be x-rayed to rule out any fracture or other complications. Then the doctor may try to pull the shoulder back into place usually with the help of gas and air for pain relief. If this is not successful, the patient may need to be anaesthetised so the shoulder can be pulled hard back into place.

2. Immobilisation

For several weeks after the initial treatment, your shoulder might have to be placed in a sling or other form of immobilization device, depending on the advice from the doctor.

3. Ice

Apply ice to the affected area for 5-10 minutes at a time three to five times per day. Make sure to wrap the ice in a thin towel to prevent an ice burn from occurring on the skin.

4. Rest

Take the time to allow your body to rest. Refrain from participating in activities where you are going to further injure the shoulder.

5. Rehabilitation Exercises

As soon as possible you should seek help from rehabilitation experts who will provide treatment and rehabilitation exercises. These exercises can help to restore the range of movement and strength in the shoulder. Rehabilitation can also help to prevent dislocating your shoulder later on down the line. The process will begin with gentle muscle exercises. Later on, weight training will be added in to the mix.

Complications Following Shoulder Dislocation

  • Frozen shoulder – the shoulder is particularly susceptible to become frozen. There are a number of reasons. First, the joint capsule is damaged around the joint, and adhesions can form which stiffen the shoulder. Second, the muscles can go into spasm to try to stop any mobility which can cause stiffness. Third, inflammation can be extensive following dislocation which can cause joint stiffness and lead to a frozen shoulder.
  • Labral tear – the rim around the socket can tear during a dislocation. If your shoulder recovers, but you keep getting residual pain in the shoulder several months or years after the dislocation then it is possible you may have a labral tear. Consult your consultant or therapist about this.
  • Recurring dislocations – due to instability after the first dislocation, more dislocations can occur. Often these are much less painful and sometimes can be relocated by the person without the need of medical help. However, after the third dislocation the patient will often seek help from a rehabilitation specialist stabilize the shoulder. If that’s not successful, stabilization surgery can be considered.
  • Neurovascular compromise – it is rare, but sometimes when the shoulder is relocated a nerve or blood vessel can get trapped in the joint. This can cause tingling or pain along the arm, and requires medical attention and possibly surgery to release the nerve or blood vessel.


  • Try to engage in exercises that are going to strengthen the rotator cuff.
  • Sports injuries are commonly associated with a dislocated shoulder.
  • Strengthen the shoulders using exercise bands, dumbbells or your own body weight for resistance under guidance from your therapist.
  • Use side elevation exercises to help increase mobility and strength in your shoulders when advised to do so.