The Effect of Extracorporeal Shock Wave Therapy on Myofascial Pain Syndrome

ABSTRACT

OBJECTIVE: To investigate the effect of extracorporeal shock wave therapy (ESWT) on myofascial pain syndrome (MPS). METHOD: Thirty patients with MPS in trapezius muscle were randomly divided into two groups, ESWT group (n=15), and trigger point injections (TPI)+transcutaneous electrical nerve stimulation (TENS) group (n=15). For a total of 3 weeks, ESWT was undertaken with 1,500 pulse each time at one week interval totaling 4,500 pulse, TPI for once a week totaling three times and TENS for five times a week totaling three weeks. RESULTS: The changes in pain threshold (lb/cm2) showed the values of 6.86+/-1.35 before first therapy, 11.43+/-0.27 after first therapy, and 12.57+/-0.72 after third therapy, while TPI+TENS group showed the values of 6.20+/-1.92 before first therapy, 8.80+/-0.48 after first therapy, and 9.60+/-2.19 after third therapy, and the changes between the groups were significantly different (p=0.045). The changes in visual analog scale were estimated to be 6.86+/-0.90 before first therapy, 2.86+/-0.90 after first therapy, and 1.86+/-0.69 after third therapy in case of ESWT group, whereas the figures were estimated to be 7.20+/-1.30 before first therapy, 4.60+/-0.55 after first therapy, and 2.80+/-0.84 after third therapy in case of TPI+TENS group, and the changes between the groups were significantly different (p=0.010). The changes in McGill pain questionnaire (p=0.816) and pain rating scale (p=0.644) between the groups were not significantly different. The changes in neck ROM were also not significantly different between the groups (p>0.05). CONCLUSION: The ESWT in patients with MPS in trapezius muscle are as effective as TPI and TENS for the purpose of pain relief and improving cervical range of motion.