Shoulder arthritis usually causes pain and limited shoulder motion. X-rays confirm the presence of arthritis. Arthritis of the acromioclavicular joint usually produces pain localized to the top front of the shoulder that is made worse by using the arm in front of the body. Shoulder strength is usually normal. Subacromial bursitis may cause catching and pain in the shoulder, but shoulder strength is maintained.
Frozen shoulder is characterized by shoulder stiffness, but the shoulder is usually strong.
Neck arthritis with nerve impingement may cause shoulder pain and weakness that is worse when the head is held in certain positions. In this case, electromyography may identify the presence of nerve involvement in the neck. However, modern diagnostic approaches usually permit a more specific diagnosis. Conditions of the rotator cuff are the most common cause of problems of the shoulder. People over the age of 40 who dislocate their shoulders are likely to have cuff tears.