Shoulder impingement is the condition of inflammation or mechanical irritation of the tendons of the shoulder joint. It is one of the most common causes of pain in the adult shoulder. The shoulder is a 'ball-and-socket' joint. A ‘ball' at the top of the upper arm bone, humerus, fits neatly into a 'socket’, called the glenoid, which is part of the shoulder blade, scapula. The acromion is a part of the scapula at the top of the shoulder. In impingement syndrome, as the shoulder moves (usually in the overhead / forward direction), the acromion may pinch on the rotator cuff tendons and the subacromial bursa, causing pain.
Impingement results from pressure on the rotator cuff from part of the shoulder blade (scapula) as the arm is lifted. It is more likely to occur in people who engage in physical activities that require repeated overhead arm movements. The pain may be due to a "bursitis" or inflammation of the bursa overlying the rotator cuff or a "tendonitis" of the rotator cuff itself. In some circumstances, a partial tear of the rotator cuff may cause impingement pain.
Individuals with shoulder impingement may experience severe pain at rest and during activities, weakness of the arm and difficulty in raising the hand overhead.
Diagnosis involves physical examination by the doctor where in the doctor checks for the possible range of movements with the affected shoulder. X-rays and MRI scans may be ordered to to evaluate for associated bony or muscular / tendinous injuries.
Conservative Treatment Options
Shoulder impingement can be treated with rest, activity modification, icing / cold therapy to the shoulder, and anti-inflammatory drugs. Physical therapy may be advised to improve range of motion and strengthen the muscles of the shoulder. Steroid injections may also be given if pain persists.
Arthroscopic surgery is recommended in patients with persistent pain and/or weakness when a teasr of the rotator cuff is identitied. Associated injuries or disorders of the bicep tendon within the shoulder, or the acromioclavicular (AC) joint are sometimes addressed during the same operation if they are also contributing to symptoms.