What is Shoulder Instability

Shoulder instability is the term used when the structures around the shoulder joint lose their ability to effectively hold the head of the humerus inside the shoulder socket [1]. In most cases this occurs following trauma of some kind, e.g. a collision during sport, however it can also occur after a minor injury or repetitive strain. The shoulder is held secure by a complex network of ligaments, rotator cuff muscles, and muscles that move the shoulder and scapular [2, 3]. Any imbalance that occurs in this network can contribute to shoulder instability [2, 3].

Shoulder anatomy.jpg


  • Generalised pain in the shoulder

  • You may feel or hear clicking with movements

  • Shoulder may feel loose, or as though it is “slipping”

  • Weakness with shoulder movements


Instability can put the shoulder at a higher risk of dislocations or subluxations in the future. If there is underlying damage to the bone or cartilage, or for those that wish to return to contact sports surgery may be recommended to reduce the risk of reoccurrence. Typically, surgical repair is done arthroscopically and results in good long-term functional outcomes [4, 5].

How can Physiotherapy help

  • Perform a comprehensive assessment of your shoulder and identify any underlying factors contributing to your pain.

  • Correction of poor shoulder biomechanics to optimise function.

  • Design a personalised exercise program to targeting muscle imbalances and restrictions in movement.

  • Provide you with education and tools for you to maintain a strong and healthy shoulder into the future.

If you have any questions regarding your shoulder pain, please give us a call at (02) 8411 2050. At Thornleigh Performance Physiotherapy, we can give you an accurate diagnosis and treatment, to help you get back in action as soon as possible. We are conveniently located near Beecroft, Cherrybrook, Hornsby, Normanhurst, Pennant Hills, Waitara, Wahroonga, Westleigh, West Pennant Hills, and West Pymble.



  1. Jaggi A, Lambert S. Rehabilitation for shoulder instability. British journal of sports medicine. 2010 Apr 1;44(5):333-40.

  2. Labriola JE, Lee TQ, Debski RE, McMahon PJ. Stability and instability of the glenohumeral joint: the role of shoulder muscles. Journal of shoulder and elbow surgery. 2005 Jan 1;14(1):S32-8.

  3. Levine WN, Flatow EL. The pathophysiology of shoulder instability. The American journal of sports medicine. 2000 Nov;28(6):910-7.

  4. Dickens JF, Rue JP, Cameron KL, Tokish JM, Peck KY, Allred CD, Svoboda SJ, Sullivan R, Kilcoyne KG, Owens BD. Successful return to sport after arthroscopic shoulder stabilization versus nonoperative management in contact athletes with anterior shoulder instability: a prospective multicenter study. The American journal of sports medicine. 2017 Sep;45(11):2540-6.

  5. Murray IR, Ahmed I, White NJ, Robinson CM. Traumatic anterior shoulder instability in the athlete. Scandinavian journal of medicine & science in sports. 2013 Aug;23(4):387-405.