Shoulder instability is a common cause of pain and dysfunction in the shoulder of athletes, especially in swimming and sports involving contact and throwing. Due to its design for maximum mobility, the shoulder is the most common site of joint instability. Early physiotherapy assessment and management is imperative with shoulder instability to ensure appropriate management and safe and timely return to sport.
What is Shoulder instability?
The shoulder is a ball and socket joint, the upper arm bone forms a large ball which sits in a shallow socket on the shoulder blade, akin to a golf ball resting on a tee. The shoulder has limited bony stability because it is designed to allow as much movement as possible (allowing us to swim, reach, lift, push, pull, throw etc).
Because of the lack of bony stability, a complex network of muscles, ligaments, cartilage and capsular structures are required to keep the shoulder in place. When the shoulder is pushed beyond the limits of normal motion these structures can be compromised and the shoulder becomes unstable and in more extreme cases can dislocate or “pop out”.
Types of instability
Atraumatic instability
Occurs over time with repetitive activities that stress the shoulder joint at its end of range such as throwing, swimming or overhead weights. Symptoms can include a gradually increasing pain in the shoulder, clicking, fear of overstretching the shoulder, weakness and heaviness.
Traumatic subluxation
Occurs with a specific event that forces the shoulder beyond its normal range of motion such as landing with the arm outstretched, getting pulled back when trying to make a tackle or getting the arm tangled overhead in a contested AFL mark or basketball rebound. The shoulder will slide out of its socket and back in which can feel like a click or a clunk followed by the symptoms described above.
Traumatic dislocation
Occurs through the same mechanisms described above but involves the shoulder sliding out of its socket and staying out until it is manually put in by a health professional. The emergency department is the best place to go in this situation to allow the shoulder to be relocated with adequate pain medication and supervision.
What should I do next?
Physiotherapy should begin immediately (once the shoulder has been relocated if necessary). Physiotherapy will begin with a thorough assessment to determine:
- The extent of tissue damage.
- The current level of function in the shoulder.
- Impairments in shoulder strength, coordination, endurance, power and flexibility that may have contributed to or been a result of instability.
- The goals of rehabilitation and best pathway to achieve those goals.
Depending on the nature of the injury, physiotherapy treatment may begin with a period of immobilisation in a sling. Atraumatic instability may require activity modification with no sling immobilisation whereas traumatic instability events may require sling immobilisation for 1-3 weeks.
Exercise based rehabilitation will begin ASAP to address impairments in shoulder strength, coordination, endurance, power and flexibility. Examples of an evidence based shoulder instability rehabilitation include the Watson MDI program. The aim of exercise rehabilitation is to prepare for return to daily functional activities and sport with bracing or taping if necessary.
It may be possible with atraumatic instability to continue sports participation with some modifications, traumatic instability may require 6+ weeks off sport if treated conservatively or 6+ months off sport if treated surgically.
Objective testing of strength allows for individualised rehab programs and criteria based activity progression. Our physiotherapists are able to utilise our Force Plates for the Athletic Shoulder test, and our AxIt Dynamometers to measure isometric muscle strength in various ranges of motion. Zone 34’s team will work with you to determine when it is safe to return to activity
Surgical Review
Conservative rehabilitation is not sufficient for the management of all shoulder instability cases. In some instances surgery must be considered. The following factors will be taken into account by your physiotherapist and orthopaedic specialist to help determine if you would benefit from a surgical approach:
- Age (younger patients have been shown to be more susceptible to recurrent instability).
- Level and type of sports participation (e.g contact vs non-contact sport).
- Extent of the damage (e.g bones, cartilage, ligaments, muscles etc).
- Congenital level of mobility (e.g general hypermobility score).
- The number of previous episodes of instability.
