Comparison of the effectiveness of radial extracorporeal shock wave therapy (rESWT) and ultrasound in chronic myofascial pain syndrome in infraspinatus muscle

Abstract

Background : Myofascial pain syndrome is one of the most frequent causes of pain in the musculoskeletal system. There are many treatments to relieve pain of the involved muscles such as dry needling and ultrasound. More
recent publications indicate a possibility of using radial extracorporeal shock wave therapy (rESWT) to treat myofascial pain syndrome, which is non invasive, effective, and has less complication.

Objectives : To determine the effectiveness of radial extracorporeal shock wave therapy and ultrasound in chronic myofascial pain syndrome in the infraspinatus muscle.

Methods : Patients with chronic myofascial pain syndrome duration more than 3 months. Forty-six patients were randomly divided into two groups: group 1 received the treatment with rESWT 1 time/week, and group 2 received the treatment with ultrasound 5 times/week. Pressure pain threshold by algometer (PPT), pain intensity by visual analogue scale (VAS), and range of motion of shoulder (ROM) were assessed before starting the treatment and every week for 6 weeks after treatment. Satisfactions were evaluated by the patients after the last treatment.

Results : There was no statistical difference between two groups in demographic data. There was statistical significance of pain reduction at the first week and subside from pain at 3-4 weeks after received the treatment in both groups. The comparison of pressure pain threshold by algometer (PPT), pain intensity by visual analogue scale (VAS), and range of motion of shoulder (ROM) before and after treatment were significantly improved in both groups (P < 0.01). Therefore, PPT significantly improved the patients in group 1 more than in group 2 (P < 0.01) but there was no significant improvement of VAS, and ROM of shoulder between the groups. At the end of the study, the satisfaction score in group 1 were significant higher than that of group 2 (P < 0.01).

Conclusions : The rESWT is more effective than ultrasound for pain reduction in the infraspinatus muscle in chronic myofascial pain syndrome.