A shoulder can dislocate when the humerus (ball of your arm) is forced out of the glenoid labrum (socket). Shoulder subluxation is a partial shoulder dislocation when the shoulder joint comes part-way out before relocating on its own. 

There are 3 ways a shoulder can be dislocated:

1. Traumatic Shoulder Dislocation – this occurs when your shoulder is in a vulnerable position and is forced out at speed. Commonly this is with your arm out to the side of you e.g. during a rugby tackle. 

2. Repetitive Shoulder Ligament Overstrain – people with more lax ligaments in their shoulders can dislocate their shoulders fairly easily. This increased passive shoulder instability is due to your anatomy or a result of repetitive overstretching of the shoulder joint. Loose shoulder ligaments make it harder for your shoulder’s stabilising muscles to maintain your shoulder stability. 

3. Multi-Directional Instability – In a small number of patients, your shoulder is unstable in multiple directions due to your genetic disposition. In these patients, the shoulder may feel loose or dislocate repeatedly in multiple directions. 

Anterior Vs Posterior: 

In 97% of first-time dislocators, the humerus is forced anteriorly (forward) out of the socket. This usually happens at force with the arm in an outstretched position. In an acute scenario, at least an Xray should be obtained to ensure no ligamentous or bony damage has been done to either the ball or the socket. 

In the other 3% of dislocations, the humerus pushed posterior (backward) out of the socket. There is usually an indirect force applied to the front of the shoulder such as in a car accident, or falling on your elbow. These should also be checked with imaging. 

If you think you had a shoulder dislocation come to WISE Emergency Clinic. We have Specialist Emergency Doctors who can treat and diagnose you within 1 hour, X-rays and ultrasounds available on-site, and an amazing team of physiotherapists SIM physio that will take care of your recovery plan.