Impingement syndrome, related to tendinitis and bursitis, also is one of the most common causes of pain in the shoulders of adults. It also can lead to further shoulder problems.

Here's what happens when you have impingement syndrome:

• Your rotator cuff and bursae become inflamed and thickened
• They can be compressed under the acromion (front edge of shoulder blade). This pinching of the rotator cuff is called "impingement" — giving the condition its name
• Sometimes a bone spur projection can cause the impingement problem