Shoulder Instability & Dislocation — What it means

Shoulder instability describes a shoulder that feels like it may “slip”, “give way”, or dislocate. This page explains the basics of the shoulder joint, what a dislocation is, why recurrence can happen, and why rehabilitation and self-management matter.

1) The Shoulder Joint (quick context)

The shoulder is a ball-and-socket joint. It trades bony stability for movement, so it relies heavily on soft tissues (capsule/ligaments, labrum, and muscles) to keep the ball centred in the socket during activity. When these structures are strained or injured, the shoulder can feel unstable. 

2) What is a dislocation?

A shoulder dislocation occurs when the ball (top of the upper arm bone) comes out of the socket. It is usually relocated (put back in) by a trained clinician, and it is preferable to use a sling for comfort in the early phase. Common types of injuries that occur during a shoulder dislocation include:

 Bankart Lesion Bony Bankart Lesion Hill Sachs Lesion

Rehabilitation typically involves progressive exercises to reduce pain and stiffness and restore function. [1]

3) Risk of re-dislocation (why it can happen again)

After a dislocation, there is an increased risk it may happen again, particularly in younger and more active people. [2] Some NHS resources note that if a first dislocation occurs before age 30, the chance of recurrent instability can be high.[3] Recurrent shoulder instability is less likely if your first dislocation is when you are 40 years or older. Dr Margie Olds (Flawless Motion Founder) has published some research that predicts whether you are likely to have recurrent shoulder instability (Predict Recurrent Instability of Shoulder (PRIS) tool).[4] The key factors that determine recurrent shoulder instability are:

  • Age (between 16-25 years)
  • Bony Bankart lesion
  • High shoulder pain and disability
  • High levels of fear or reinjury
  • Not being immobilised
  • Dislocation in your dominant arm

You can assess the likelihood that you will have recurrent shoulder instability using the PRIS tool yourself

Access the PRIS tool


Common reasons recurrence happens

  • Soft tissue healing: the capsule/ligaments may be stretched or torn and need time and progressive loading to recover.
  • Strength & control: shoulder and shoulder-blade muscles may be inhibited after injury and need retraining.
  • Confidence/apprehension: fear of re-injury can change how you move by altering movement patterns and load on the shoulder. 
  • Demand: contact/overhead sport or heavy work can expose the shoulder to higher-risk positions.

4) Why self-management and rehabilitation matter

Early advice and a structured home programme can make a meaningful difference. NHS guidance commonly recommends shoulder exercises to help reduce pain and stiffness and support recovery. [1] Patient leaflets also emphasise that rehabilitation starts early after relocation and that it is important to rebuild strength and regain comfortable movement without fear of re-dislocation. [4]

What “good rehab” usually includes

  • Restore movement gradually without forcing.
  • Rebuild strength (rotator cuff, scapular muscles, and global upper limb strength).
  • Improve control in positions that matter for your sport/work.
  • Progress activity step-by-step (volume first, then intensity).

If your shoulder continues to feel unstable, repeatedly “slips”, or you’re returning to high-demand sport/work, consider getting individualised assessment and guidance.

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