What is shoulder instability?

Shoulder instability is a condition in which the joint capsule and/or surrounding rotator cuff muscles of the shoulder become stretched out or weak. The result is a state in which the shoulder can become unstable or dislocated with normal daily activity. If the shoulder does dislocate, chances are that it will dislocate forward (anteriorly) as is the case with about 95% of these injuries according to research. The position that is most likely to cause a dislocation if instability is present is when the arm is positioned overhead and cocked (similar to the throwing motion). Dislocations can also damage the surrounding cartilage (labrum) of the shoulder resulting in a Bankart or Hill-Sachs lesion creating even more instability of the joint.