Why do shoulders dislocate so often!?
There are multiple factors contributing towards that answer…
The First and most obvious one is the shape of bones that comprise the shoulder joint. The joint capsule surface is only mildly concave when compared to the hip. This means that it is easier for the head of the humerous (the upper arm bone) to slip out of the socket. The shoulder does have a labrum to deepen the socket and increase the surface area of the joint however even with the labrum the joint is only mildly concave compared to other “ball and socket” joints. (1)
The Second is the strength or laxity of your ligaments. Because the joint shape is poor for stability, the ligaments are more heavily relied on for keeping the shoulder in the joint. The ligaments of the shoulder combine with the joint capsule and wrap around the entirety of the joint. They provide stability to the shoulder throughout range as different portions become taught based on the flexion, extension, abduction or rotation of the humerus in the socket.
The Third is the strength and activation of your muscles. The muscles add dynamic support to the shoulder throughout range to maintain the position of the head of humerous in the socket when placed under load. When the load exceeds the support the muscles can provide, the support offered by the joint shape and ligaments is seldom enough to prevent dislocation. (2)
How do I prevent it?
Looking at the factors above, a deficit in any of these areas is the first point of call when looking for what to address. This is clinically known as shoulder instability. The shape of the joint can’t be changed but understanding anatomically vulnerable positions of the joint can assist with avoiding high load in those positions. Ligaments are a passive supportive tissue but being aware of any ligament laxity and pre-existing risk of dislocation will help you to make a more informed decision about your safety when doing certain activities of high load and strain. The same can be said of understanding your own muscle strength and knowing when to ask for help if the activity requires the shoulder being under high load or in an anatomically vulnerable position. Increasing your muscle strength and bulk will help to make the shoulder more stable and stronger when lifting heavier weights or when in a vulnerable position. This does not make it impossible to injure or dislocate the shoulder but does effectively reduce the risk of dislocation.
I’ve dislocated my shoulder, what now?
If you have dislocated your shoulder, you should seek further professional advice in order to ensure you regain full function and effective rehabilitation to prevent reoccurrence. A good place to start is by seeing a physiotherapist or an exercise physiologist who have a greater level of training on how to treat and rehabilitate injured tissues. We will assess your shoulder and based on your physical assessment formulate a treatment that is relevant for you with your current level of injury and strength along with progressions to get you back to the jobs, sports and activities you love doing most. (2,3)
My Shoulder dislocates often and easily, can anything fix it?
If chronic or recurrent shoulder dislocation is something you suffer from there is likely damage to the ligaments of the shoulder and continued weakness in your shoulder and rotator cuff muscles. If you haven’t already, you should be seeing a physiotherapist or exercise physiologist. We will endeavour to improve your function as much as possible with the right training and education to minimise your risk of dislocation. If this still is not enough to prevent your recurrent dislocations we may discuss your presentation being managed by a specialist who can talk about other treatment and surgical options that may be available to you.
If you are concerned or think you might have suffered a shoulder dislocation, please contact us to book a session with one of our friendly physiotherapists for further assessment. We look forward to seeing you soon.
By Josiah Turnbull
- Washington University Orthopedics. 2021. The Anatomy Of The Shoulder. [online] Available at: <https://www.ortho.wustl.edu/content/Patient-Care/3127/Services/Shoulder-Elbow/Overview/Shoulder-Arthroscopy-Information/The-anatomy-of-the-shoulder.aspx
- Jaggi, A. and Lambert, S., 2010. Rehabilitation For Shoulder Instability. [online] British Journal of Sports Medicine. Available at: https://bjsm.bmj.com/content/44/5/333.info
- Kavaja, L., Lahdeoja, T., Malmivaara, A. and Paavola, M., 2021. Treatment after traumatic shoulder dislocation: a systematic review with a network meta-analysis. [online] British journal of Sports Medicine. Available at: https://pubmed.ncbi.nlm.nih.gov/29936432/