Many athletes and weekend warriors can develop shoulder discomfort or pain, particularly if they perform repetitive overhead motions. Whether it is throwing a baseball, hitting an overhead smash, swimming the butterfly, or simply painting a wall, repeated overhead motions can become very painful if your rotator cuff is not functioning properly. Shoulder impingement is one of the most common causes of pain in the shoulder. It results from the rotator cuff being pinched between the humerus and the scapula.
The rotator cuff is made up of four muscles: the supraspinatus, the infraspinatus, the teres minor, and the subscapularis. The job of this quartet is to depress the shoulder joint when performing overhead activities. The acromion is the front of the scapula or shoulder blade. It sits just above the humeral head and rotator cuff tendons. When the rotator cuff is insufficient, the acromion rubs or “impinges” on the tendons when the arm is lifted overhead, causing pain and inflammation.
There are three main risk factors for developing shoulder impingement. First is anatomy. If you have a Type III or “hooked” acromion, you are more predisposed to shoulder impingement. Secondly, weakness in your posterior cuff (infraspinatus/teres minor) can cause abnormal shoulder mechanics leading to impingement. This is not dissimilar to driving on a flat tire – if one tire is flat, the car will pull to the side; if one of your rotator cuff muscles is not functioning properly, your shoulder will not be in the correct position for overhead movements and will impinge. Lastly, tightness or decreased range of motion (particularly, internal rotation) may increase your risk of shoulder impingement. Recent studies suggest that athletes with a 20% deficit in internal rotation (range of motion) in the dominant shoulder are more likely to experience a rotator cuff injury.
If you are experiencing any of these symptoms, consult with your doctor. An orthopedist may obtain an X-ray to determine the amount of clearance in the subacromial joint space and the type of acromion. If symptoms do not improve, an MRI may be ordered to see if there is any damage to the rotator cuff muscles.
Conservative treatment consists of activity modification, ice, and anti-inflammatory medication until symptoms subside. Your orthopedist may also provide a cortisone injection to decrease inflammation (don’t worry, it won’t hurt much). It is also recommended to limit overhead activities, even overhead rotator cuff strengthening, until the impingement symptoms resolve. As hunched-forward or slouched posture diminishes the size of the subacromial space and can lead to shoulder impingement, it is easily corrected with physical therapy. Physical therapy treatment would consist of postural strengthening, periscapular and rotator cuff strengthening and stretching.
If all conservative measures fail, your orthopedic surgeon may suggest a subacromial decompression which would create more joint space for the rotator cuff tendons. It should be noted that surgical procedures create approximately 1 cm of space, while postural strengthening can create closer to 2.5 cm of relative subacromial joint space, so it would seem wise to employ conservative treatment such as rotator cuff and postural strengthening initially. Eventually, with luck and hard work, most are able to return to full pain-free athletic competition.
Shoulder impingement is common in over-head athletes and is usually resolved con-servatively, especially if it is diagnosed and treated early. The longer that the rotator cuff is impinged, the more damage can occur. So, if you are having any of these symptoms while performing overhead activities, consult your orthopedic surgeon and get back in the game.