In order to study the frequency and the site of pain with shoulder impingement syndrome accompanied by myofascial pain syndrome (MPS), and to see how the treatment of impingement syndrome effects the improvement in myofascial pain.

Among patients diagnosed with shoulder impingement syndrome with MPS and who complained around of shoulder muscle pain 53 subjects were selected as subjects for this study. Patients were divided into three groups according to method of treatment; the first group was the cases who received impingement injection test, the second group were only carried out isometric strengthening exercise of the periscapular muscles and the rotator cuff, and the third group was the cases who failed conservative treatment and had a surgical operation. All subjects had a physical examination before treatment to see if the MPS was present in the muscles around the shoulder, the range of motion of shoulder, and the American Shoulder and Elbow Society (ASES) shoulder score were measured.

There was no relation to between age, gender, impingement signs, tenderness around the joints, the range of motion and ASES shoulder score. The VAS was reduced from 6.2±2.3 to 1.2±1.5 (p<0.01), and ASES shoulder score increased from 32.1±15.3 to 87.5±17.7 (p<0.05). The differences among treatments of the three groups were not significant in pain and treatment outcome (p>0.05).

Treatment of shoulder impingement syndrome reduced the symptoms of MPS, thus shoulder impingement syndrome can be the one of the causes of MPS.