One of the most common physical complaints is shoulder pain. Your shoulder is made up of several joints combined with tendons and muscles that allow a great range of motion in your arm. Because so many different structures make up the shoulder, it is vulnerable to many different problems. The rotator cuff is a frequent source of pain in the shoulder.

This illustration of the shoulder highlights the major components of the joint.

Anatomy

Your shoulder is made up of three bones: your upper arm bone (humerus), your shoulder blade (scapula), and your collarbone (clavicle).

Your arm is kept in your shoulder socket by your rotator cuff. These muscles and tendons form a covering around the head of your upper arm bone and attach it to your shoulder blade.

There is a lubricating sac called a bursa between the rotator cuff and the bone on top of your shoulder (acromion). The bursa allows the rotator cuff tendons to glide freely when you move your arm.

Description

The rotator cuff is a common source of pain in the shoulder. Pain can be the result of:

• Tendinitis. The rotator cuff tendons can be irritated or damaged.
• Bursitis. The bursa can become inflamed and swell with more fluid causing pain.
• Impingement. When you raise your arm to shoulder height, the space between the acromion and rotator cuff narrows. The acromion can rub against (or "impinge" on) the tendon and the bursa, causing irritation and pain.

Cause

Rotator cuff pain is common in both young athletes and middle-aged people. Young athletes who use their arms overhead for swimming, baseball, and tennis are particularly vulnerable. Those who do repetitive lifting or overhead activities using the arm, such as paper hanging, construction, or painting are also susceptible.

Pain may also develop as the result of a minor injury. Sometimes, it occurs with no apparent cause.

Symptoms

Rotator cuff pain commonly causes local swelling and tenderness in the front of the shoulder. You may have pain and stiffness when you lift your arm. There may also be pain when the arm is lowered from an elevated position.

Beginning symptoms may be mild. Patients frequently do not seek treatment at an early stage. These symptoms may include:

• Minor pain that is present both with activity and at rest
• Pain radiating from the front of the shoulder to the side of the arm
• Sudden pain with lifting and reaching movements
• Athletes in overhead sports may have pain when throwing or serving a tennis ball

As the problem progresses, the symptoms increase:

• Pain at night
• Loss of strength and motion
• Difficulty doing activities that place the arm behind the back, such as buttoning or zippering

If the pain comes on suddenly, the shoulder may be severely tender. All movement may be limited and painful.