Shoulder instability

Shoulder instability happens when the top of your upper arm bone is forced out of its socket because of injury or overuse and repeated stress on the joint (or a combination of the two).

You need to know that if this happens once, your shoulder joint can become loose and you’re more vulnerable to repeat shoulder injuries. This is referred to as chronic shoulder instability.

Note that some people with shoulder instability have never dislocated their shoulders or experienced a similar severe injury. Many lifestyle factors and even how your body is naturally built can result in shoulder instability.

For example, perhaps you naturally have shoulder ligaments that are more loose, (just because that’s your unique anatomy), or you regularly participate in sports that require a lot of overhead repetitive overhead motion like tennis, baseball, rugby, swimming, or volleyball.

Or perhaps your job requires lots of overhand motion and lifting heavy things above your head.

Regardless of the cause, having loose shoulder ligaments makes it difficult to maintain shoulder stability, especially if you are still engaging in repetitive activities or ones that put a significant amount of stress on your shoulder.

Some people may be “double-jointed” and have naturally loose ligaments in their shoulders and throughout their entire bodies, which can cause the shoulder joints to become unstable even without a history of injury or repetitive stress.

Another type of shoulder instability is referred to as anterior shoulder instability (and can cause anterior shoulder pain) or anterior glenohumeral instability, which occurs when the humeral head of the shoulder subluxates or dislocates from the glenoid fossa, causing the function and range of motion of the shoulder joint to be compromised, often leading to recurrent shoulder instability.

What’s more, the cartilage rim around the edge of your glenoid – the labrum – may be torn as well, and this is referred to as a Bankart lesion. While the initial dislocation may not cause an extreme amount of pain or trauma, it can lead to continued disc locations, your shoulder joint giving out, and prolonged pain and instability, all of which may require surgery.

These individuals may experience multidirectional instability, which means that the shoulder joint has become unstable without a history of injury or previous significant pain.