Shoulder instability is very common and it accounts for over half of all shoulder related injuries in people aged 13-30 and is still very prevalent in people aged 31-45. The shoulder joint is the most mobile joint in our body allowing us to move our arms in many different directions. Any time we have more mobility in a region we sacrifice stability, and vice versa. This means that the shoulder is also the most unstable joint in the body. The shoulder joint is the most commonly dislocated joint in the body and accounts for around 50% of all joint dislocations. It is estimated that over 95% of the time the shoulder will dislocate anteriorly (meaning it dislocates in a forward direction) due to a lack of ligament support in this region. Shoulder instability is often the result of rotator cuff weakness in conjunction with low or high energy trauma. The shoulder joint consists of the humerus and the glenoid fossa (the shoulder socket) and as a result of trauma or weakness the humerus can glide out of the fossa. If the humerus glides out of the fossa before returning to its position it is referred to as a subluxation. If the humerus glides out of the fossa and does not return to its position it is referred to as a dislocation. People often report feeling a "clunk" and then an inability to move the arm. If the humerus subluxes and relocates the person will report can often report two different clunks where they initially lost motion and then got some motion back after the second clunk. But they tend to have high levels of pain and reduced motion after the injury. In the case of a dislocation it may be one major clunk and then an inability to move the arm again without a return to its prior position. If the dislocation is large it may require open eduction to put the shoulder back in place and sometimes may be accompanied by a compression fracture called a Hills Sach's Lesion where the force of the humerus dislocating was so strong it hits against the shoulder socket causing a break/dent. Once a shoulder subluxes or dislocates it is prone to happening again. This is why physical therapy is so important. In physical therapy we work to ensure that this does not happen again by performing the right exercises to keep the shoulder in its socket. 

 

After this type of injury patients tend to have shoulder pain, limited range of motion,  and apprehension to movement. Our first goal is to minimize pain and restore the range of motion lost. Once this is achieved we work to build strength in the shoulder and scapular muscles, especially the rotator cuff muscles. The rotator cuff muscles are essential in preventing the reoccurrence of shoulder dislocation because their job is to keep the shoulder in the socket. Treatment for shoulder instability tends to have excellent results in physical therapy. Please see photos below for some examples of how we treat shoulder instability in our clinic. If you would like to schedule an appointment please reach out to us. 

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