Shoulder impingement syndrome is caused by excessive squeezing or rubbing of the rotator cuff and shoulder blade. When the muscles and tendons don’t slide easily and normally, the tendons and bursa (a fluid-filled sac that protects the tendons) become irritated and swollen, causing pain.
With this syndrome, the space between the shoulder blade and rotator cuff narrows. If shoulder impingement syndrome is severe, it can lead to a more serious injury to the rotator cuff over time, where the cuff develops a small tear in the tendon.
The symptoms of shoulder impingement syndrome include:
- Difficulty reaching up behind the back
- Pain when the arms are extended above the head or out away from the side of the body
- Catching or grating of the muscles when you rotate or raise your arm
- Shoulder weakness
- Not being able to sleep on the affected side because of the pain
In cases where the rotator cuff has torn completely, patients have very significant weakness and sometimes cannot raise their arm against gravity.
Shoulder impingement syndrome is closely related to shoulder tendinitis and bursitis of the shoulder and may occur in association with these other conditons.
Conservative treatments for impingement syndrome include ice, over-the-counter anti-inflammatory medications, and most importantly, physical therapy. Symptoms may slowly go away over a period of weeks. It may take several months to recover fully, and activities that cause pain should be avoided, such as stretching or reaching past your comfort zone.
In cases of severe pain, a cortisone injection may help reduce symptoms.
If the patient still has symptoms after these treatments, an MRI may be necessary to rule out a rotator cuff tear.