Shoulder Pain explained by Zach Perlman DO, Princeton Spine & Joint Center
“Shoulder pain is very common in athletes and also in the general population and this is because the shoulder is the most mobile joint in your body. The function of the shoulder joint is to lift the arm, to rotate the arm and to reach for overhead objects. Because of this mobility, it’s very vulnerable to injury. It can happen in an acute setting, for instance, getting tackled by a football player or it can happen from repetitive over use injury where the bone gets dislodged out of the shoulder joint.
It’s important to understand the anatomy of the shoulder joint. If we’re going to talk about shoulder pain. There are three main bones that make up the shoulder joint. There’s the humorous, there’s the clavicle or collarbone, and then there’s the scapula or shoulder blade. The shoulder joint is a very shallow joint, so the labrum helps to deepen the joint. The labrum is a cartilage structure that is in the glenohumeral joint. The next layer or the ligaments. There’s a tough ligamentous structure called the capsule and then we have the glenohumeral ligaments. Also very important in the shoulder is the rotator cuff. The rotator cuff is thought of as the dynamic stabilizer of the shoulder. As the arm is being in ab-duction or away from the body, the rotator cuff contracts to keep equal space maintained in the glenohumeral joint.
There are two types of injuries I would like to discuss. The first being a dislocation. That is when the humerus is dislodged out of the glenoid cavity. There can also be a partial dislocation which is known as a subluxation event. The second type of injury is a repetitive strain. This is seen in adolescent athletes such as swimmers, tennis players and volleyball players and it is seen in the general population in patients that are doing overhead activity which is repetitive such as painting.
There are a subset of patients that have what is known as multidirectional instability or MDI. These are the patients that tell their friends they are double jointed, where they can bring their thumb all the way back to their form or their knees have dislocated in the past. These patients may not know that they have loose ligaments in their shoulder as well. Because the ligaments are loose, the glenohumeral joint can dislocate from the front, the back, or the bottom of the joint.
If you are having chronic shoulder pain, you should go see your physician to be evaluated for chronic shoulder instability. The diagnosis may be made on physical exam, but if there’s any concerning features, it may be warranted to get an x ray or an MRI. X Ray shows the bones MRI or MR Arthrogram shows the soft tissues. The arthrogram helps to evaluate the labrum for any damage. If you or anyone that you know is suffering with chronic shoulder pain, feeling their shoulder is giving out, feeling looseness in the shoulder or feeling popping, clicking or catching, or any mechanical sensation in their shoulder, you should be evaluated by your doctor for chronic shoulder instability.”
~Zach Perlman, DO