All the Right Shoulder Moves

Two joints in the body that are made for movement are the hinge joint and the ball and socket joint. The elbow and knee are hinge joints. The shoulder and hip are ball and socket joints.

When the arm is lifted overhead, the ball part of the shoulder (called the head of the humerus) drops down and back in the socket. If there isn't enough space for this to happen, the rotator cuff tendons can get pinched. This is called impingement.

Impingement can be caused by many factors. There may be a loss of blood supply to the area or aging and damage to the rotator cuff. Changes in the way the joint moves can narrow the space inside the shoulder joint. Altered joint movements can also worsen impingement problems.

If the ball doesn't stay centered, it may slide around and get too close to other structures in the shoulder. Impingement may result. Sometimes the back of the shoulder joint gets tight. This forces the ball up and forward as the arm is raised. This too can cause impingement.

Treatment of shoulder impingement involves strengthening the muscles around the joint, especially the rotator cuff muscles. Stretching tight tissues, especially in the back of the shoulder joint, is also important. These two treatments help to restore the normal movement of the ball in the socket. Learning more about how the shoulder joint actually moves will help improve treatments for shoulder impingement.