Shoulder Instability

Shoulder instability is classified as a condition where the top of the arm, the ball, moves outside of its normal anatomical limits. If the ball comes fully out of the socket, it is referred to as a dislocation. Otherwise, subluxation is the term used to classify a situation where the ball has partially come out of the socket. The shoulder joint (gleno-humeral joint) operates as a ball and socket joint. These types of joints allow for extreme ranges of motion. Some people have inherently loose shoulder joints and this places them at a greater risk of instability.

Shoulder instability is most common in patients aged younger than 40 years old. Football, surfing and skiing are the most common causes of shoulder instability, workplace injuries is another. If a patient has hypermobile joints, they are at greater risk of suffering shoulder instability.

Dislocation may be extremely painful. Usually, attendance at a hospital for treatment is recommended. Analgesic medication may be required for the next few days and a sling may be worn. An X-Ray of the shoulder is required in all cases of subluxation and dislocation.

An injury of this nature may be complicated by damage to the surrounding bone, cartilage of the shoulder, lining of the shoulder or surrounding muscles or nerves. If any of these symptoms have occurred, further investigations will be required. Following dislocation, surgery may be considered. This may manifest as minimally invasive surgery or surgery through an open incision. The type of surgery needed depends on the extent of damage and expected future demands on the shoulder. If significant damage has been sustained to the shoulder and the patient is active a reconstruction may be recommended.

In those less active patients who have little structural damage to the shoulder, physical therapy can help stabilize the shoulder without resorting to surgery in many cases.

The recurrence rate for shoulder instability is high: over 90% in 20 year old males. Subsequent shoulder instability can do more damage to the shoulder. This can predispose towards osteoarthritis.


  • All shoulder dislocations require medical assessment.
  • A high Recurrence rate in younger patients.
  • If you are inherently “loose” in the shoulder ligaments, the injury risk is greater.
  • Rehabilitation with a sports physiotherapist is required.
  • Surgery may be required depending on the extent of the injury.