Efficacy of conventional ultrasound therapy on myofascial pain syndrome: a placebo controlled study.

OBJECTIVES Myofascial pain syndrome (MPS) is a complex pain syndrome characterized with trigger points (TP) in skeletal muscles. We aimed to assess the efficacy of ultrasound (US) therapy, which is one of the main devices used in physical medicine and rehabilitation, for the treatment of TP in MPS. METHODS Fifty nine patients (49 females, 10 males) with active TP on the upper trapezius fibers were randomized into the treatment (n=30) and the control groups (n=29). The treatment group received conventional US therapy for 6 minutes, on 1.5 Watt/cm2 dose with 1 MHz frequency for 15 days whereas a placebo US therapy was administered to the control group. Prior to the treatment, immediately and 3 months later pain severity during rest and physical activity was assessed with visual analog scale (VAS), TP tenderness was measured with 0-5 scale, pressure pain threshold (PPT) was analyzed with algometer and the depression level was evaluated with Beck's depression questionnaire (BDP) by a clinician blinded to the groups. RESULTS The mean age of the patients were 37.43±9.07 and 35.83±5.68 years, in the treatment and control groups, respectively. Compared to the pre-treatment values VAS, 0-5 scale and BDP scores decreased (p<0.01) along with an increase in PPT (p<0.01) in both groups at the follow-up visits. 0-5 scales and BDP scores were significantly lower and PPT was significantly higher in the treatment group, compared to the control group (p<0.001). CONCLUSION Our results revealed that US treatment is effective on MPS.