Shoulder dislocation may be caused by;
- A large impact force to the shoulder from behind
- An awkward twisting arm movement
- A combination of both
Partial shoulder dislocation or subluxation injury is typically caused by repetitive arm movements, like pitching a ball or pulling a rope, that stretch the shoulder labrum. These types of injuries are often slow onset injuries that worsen over time, however, if the movement is forceful enough, they may cause immediate pain and instability.
Complete shoulder dislocation injury is caused by receiving a direct impact to the shoulder from in front or behind or from falling on an outstretched arm or elbow, where a large amount of force causes complete dislocation of the ball from the socket of the shoulder.
Sports Injuries

Sports like cricket, sailing, throwing and weightlifting commonly cause SLAP tears (superior labral tear from anterior to posterior) which are also known as partial dislocation injuries. They involve repetitive, forceful movements at the top of the shoulder joint and as such cause partial dislocation injury to the top of the shoulder. Sports people can still use their shoulder after a SLAP tear and so often keep playing although the movement becomes increasingly more painful and less stable. Playing sport with a SLAP tear increases the risk of further injury. Contact sports like rugby, AFL, football, netball and basketball are commonly the cause of Bankart lesions which are complete dislocation injuries at the front of the shoulder, sustained by an impact to the shoulder from behind as the outstretched arm is pulled backward. Sports like skateboarding and cycling often cause dislocation by falling on an outstretched arm, where the impact forces the arm bone backwards out of its socket (known as posterior shoulder dislocation).
Workplace Injuries
Repetitive workplace activities like painting, plastering, and pulling on ropes commonly cause partial dislocation injury to the top of the shoulder known as SLAP tears. Slow onset shoulder injuries can worsen over time and many people delay seeking treatment as the pain and loss of movement is usually minor, however, repeated movements can risk more serious injury and complications. Carrying heavy objects overhead in awkward positions, like firefighters or construction workers do, may cause Bankart lesions, or complete shoulder dislocation at the front of the shoulder, whereby the shoulder slips out of the socket. Workplace falls, common in the mining industry, public transport and school teaching, where the environment is often unpredictable, may cause partial or complete shoulder dislocation by landing on an outstretched arm or rigid elbow which forces the ball off the socket of the shoulder.
Chronic Shoulder Pain
A chronic injury is an injury which is caused by repeated episodes of minor injury over a period of more than 6 months, which results in increasing pain, swelling and inflammation gradually. Shoulder dislocation injuries can become chronic shoulder dislocation injuries if they are not treated correctly and reoccur with regular frequency. SLAP tears are common shoulder dislocation injuries which may develop into chronic shoulder pain conditions whereby the labrum and biceps tendon at the top of the shoulder joint become chronically inflamed.
Degenerative Joint Disease
Degenerative joint disease in shoulders is a painful condition, often resulting from dislocation or injury. Deterioration of the shoulder joint, muscles and tissues around it damages the joint’s surface and it worsens over time – a bit like a crack in a car windscreen. The pain, inflammation and stiffness make daily living difficult, therefore treatment is essential in order to resume a good quality of life.