Can you offer any suggestions? Our daughter is a very athletic cheerleader. She participates in competitions all over the place. She's complaining of shoulder pain along the back of her shoulder. It hurts to move her arm overhead. It hurts when she presses on that spot. Yet no one can find anything wrong. Even the arthroscopic exam was negative. What do we do now?

Shoulder pain is a common problem among athletes of all kinds. Cheerleaders are athletes in every sense of the word. They use wide arcs of motion in their arms, which can cause a variety of problems.

Some possible causes of posterior shoulder pain in this type of athlete include tendinitis (inflammation of the tendon) or tendinosis (degeneration of the tendon without inflammation). Rotator cuff or labral (cartilage) tears are also possible.

We assume these possibilities have been ruled out but it's always good to ask. One other less common cause of posterior shoulder pain is the quadrilateral space syndrome (QSS). QSS is easily overlooked in athletes but can severely limit overhead function.

The underlying problem in QSS is a compression or pinching of the axillary nerve as it exits the back of the shoulder. Quadrilateral refers to the four-sided shape of the anatomy (both muscles and bone) where the nerve is located.

QSS can best be diagnosed using an axillary nerve block. A numbing agent such as lidocaine is injected into the area. If the painful symptoms go away after the injection, the test is considered positive.

Sometimes the injection is enough to treat the problem. In other cases, surgery is needed. Most often, a course of physical therapy is tried first to avoid surgery. The therapist may be able to reduce pressure on the nerve and help it glide freely through the soft tissues. Manual therapy including nerve mobilization techniques is used.