Shoulder instability

The instability of the shoulder joint can be in one direction for example, anterior instability (out the front), posterior instability (out the back) or in more than one direction (known as multidirectional instability). Anterior is the most common form of instability and is probably because the joint capsule is at its weakest at the front of the joint.

What are the causes of shoulder instability?

This condition can be caused by a number of reasons.  If the joint surfaces are shaped slightly differently – for example if the glenoid fossa is slightly flatter than usual, or the head of humerus is more of an oval shape – the joint may not be as stable compared with other people who have “normal” joint anatomy.

Instability may be caused by:

Trauma (traumatic instability)

• This is usually due to a particular accident or injury which damages the structures that provide stability
• This is sometimes due to an old injury – for example an injury which weakens the capsule may cause instability – known as “post traumatic instability”

Joint Laxity (a traumatic instability)

• Could possibly be due to:
• anatomical abnormalities
• generalized laxity (known as hypermobility)
• muscle weakness
• certain conditions, including pregnancy

“Acute on chronic” instability – a traumatic injury to an already lax joint

Useful Products:

• Shoulder Braces - help to support and stabilize the shoulder, reducing the risk of further injury.
• Cold Therapy Shoulder Wrap - simple and mess free way to apply cold therapy to the shoulder area, helping to relieve pain and inflammation.

Please see the Virtual Sports Injury Clinic for more information on how to treat Shoulder Instability