Written By Jim Moran, PT, Shoulder Specialist
What is shoulder impingement?
This condition can also be referred to as thrower’s shoulder or swimmer’s shoulder. Shoulder Impingement is when the all important rotator cuff tendons become pinched in the subacromial space. The subacromial space is where two bones, the acromion (roof of the joint) and the humeral head (the ball of the upper arm bone), come almost together creating a narrow passage way in which the supraspinatus (one of the four rotator cuff muscles) tendon must pass through. Under optimal conditions the rotator cuff tendon is not getting rubbed, infringed upon or pinched in this tight space. During impingement, the rotator cuff tendon is pinched between the acromion and the humeral head causing inflammation, fraying and tearing if this condition is not corrected.
What causes impingement in the overhead athlete?
Any condition that further narrows the subacromial space can cause impingement in the athlete’s shoulder, including:
- Rotator cuff muscle weakness: from injury or poor conditioning relative to the volume of activity, creates abnormal superior migration of the humeral head as the ball usually stays low in the pear shape socket.
- Instability of the glenohumeral (shoulder) joint: where the dynamic stability (created by muscle power) is not sufficient enough to overcome the ligamentous laxity (static instability), created by adaptive loosening over years of overhead sport.
- Rounded forward shoulder posturing: resulting from a combination of tight chest muscles and weak upper back muscles, which have been shown by X-ray studies to shrink the subacromial space, causing impingement.
What does the overhead athlete experience with impingement?
Pain in the shoulder, often times pain radiating up to four inches down the arm, tightness in the back of the shoulder, a popping sensation and weakness. The shoulder can still perform athletically however, with symptoms and not optimally.
What can be done to resolve impingement?
Treatment for impingement is to increase the subacromial space. Increasing the room available for the tendon will allow the swollen tendon to heal. Over the counter anti-inflammatory medication and ice are commonly recommended. Strengthening the rotator cuff muscles, the scapular stabilizers and the postural muscles will take care of the three causes of shoulder impingement in the overhead athlete. In most cases of impingement the athlete will be able to start standard and focused tubing and rotator cuff weight workouts, which will correct the weaknesses causing impingement.