What Is Impingement Syndrome?
Shoulder pain when raising your arm may mean you have impingement syndrome. This is pinching within your shoulder. The problem may have been caused by repeating an overhead motion. In some cases, you may feel a nagging pain even when you’re not using your shoulder.
A forceful action repeated day after day without rest can cause a repetitive motion injury (RMI). Shoulder impingement is often due to an RMI.
Symptoms of impingement
You may feel pain, pinching, or stiffness in your shoulder. Pain often comes with movement. But you may also feel it when you’re not using your shoulder. For example, you may feel pain while trying to sleep.
Causes of impingement
Shoulder impingement is often caused by making repeated overhead movements. Constant shoulder use can irritate the tendons and bursa, leading to swelling. Swollen parts of the shoulder take up more room, making the joint space smaller:
Bursitis is inflammation of the bursa, a sac of fluid that cushions shoulder parts as they move. The bursa fills up with too much fluid, filling and squeezing the joint space.
Tendinitis is inflammation of the tendons, fibrous tissues that connect muscle to bone.
Bone problems can make impingement worse. The acromion is part of the shoulder bone. It may be flat or hooked. If your acromion is hooked, the joint space may be smaller than normal. This makes you more prone to shoulder problems. Bone spurs (growths on the bone) can also narrow the joint space.