THE IMMEDIATE EFFECTIVENESS OF ELECTRICAL NERVE-STIMULATION AND ELECTRICAL MUSCLE STIMULATION ON MYOFASCIAL TRIGGER POINTS

This study is designed to investigate the immediate effectiveness of e lectrotherapy on myofascial trigger points of upper trapezius muscle. Sixty patients (25 males and 35 females) who had myofascial trigger po ints in one side of the upper trapezius muscles were studied. The invo lved upper trapezius muscles were treated with three different methods according to a random assignment: group A muscles (n = 18) were given placebo treatment (control group); group B muscles (n = 20) were trea ted with electrical nerve stimulation (ENS) therapy; and group C muscl es (n = 22) were given electrical muscle stimulation (EMS) therapy. Th e effectiveness of treatment was assessed by conducting three measurem ents on each muscle before and immediately after treatment: subjective pain intensity [(PI) with a visual analog scale], pressure pain thres hold [(PT) with algometry], and range of motion [(ROM) with a goniomet er] of upper trapezius muscle (lateral bending of cervical spine to th e opposite side). When the effectiveness of treatment was compared wit h that of the placebo group (group A), there was significant improveme nt in PI and PT in group B (P < 0.01) but not in group C (P > 0.05). T he improvement of ROM was significantly more in group C (P < 0.01) as compared with that in group A or group B. When each group was divided into two additional subgroups based on the initial PI, it was found th at ENS could reduce PI and increase Pi significantly (P < 0.05), but-d id not significantly (P > 0.05) improve ROM, as compared with the plac ebo group for both subgroups. EMS could significantly (P < 0.05) impro ve ROM, but not PT, better than the placebo groups, for either subgrou p. It could reduce PI significantly more (P < 0.05) than placebo contr ols only for the subgroup with mild to moderate pain, but not with sev ere pain. For pain relief, ENS was significantly better (P < 0.05) tha n EMS; but for the improvement of ROM, EMS was significantly better (P < 0.05) than ENS. It is concluded that ENS is more effective for imme diate relief of myofascial trigger point pain than EMS, and EMS has a better effect on immediate release of muscle tightness than ENS.