You may have a shoulder impingement. This is when the rotator cuff tendon(s) get caught between the top of the shoulder and the bottom of the acromion. The acromion is a bone above the shoulder joint that curves over part of the rotator cuff. The rotator cuff is made up of four muscles and their tendons that surround the shoulder joint.

There are special tests that can be done to find out what is the exact problem. A doctor or physical therapist will move your arm and shoulder through a series of motions. Each test helps identify which soft tissue structures are involved. If the rotator cuff is involved the specific muscle can be identified.

If impingement isn't the cause of your symptoms, you may have a torn capsule or other structural problem. An MRI may be ordered to confirm the exam findings.