Comparison of two different techniques of electrotherapy on myofascial pain

Abstract

This study was designed to compare the effects of Transcutaneus Electrical Nerve Stimulation (TENS) and Electrical Muscle Stimulation (EMS) on myofascial trigger point (MTrP) of the upper trapezius muscle.

A total of 40 patients were randomly divided into three groups. All patients had active MTrP in one side of the upper trapezius muscles. Group I was treated with TENS and trapezius-stretching exercises; Group II was treated with EMS and trapezius-stretching exercises and Group III, the control group, had only trapezius-stretching exercises. Subjective pain intensity with VAS, range of motion (ROM), and pain threshold (PT) were assessed before, immediately after two week treatment and 3 months after treatment.

Group I had a statistically significant reduction in VAS ( $\mathit{P}\mathrm{<}0.01$ ), increase in PT and ROM ( $\mathit{p}\mathrm{<}0.05$ ) at end of the treatment when compared with the control group. Only VAS was significantly improved ( $\mathit{p}\mathrm{<}0.05$ ) in the Group II patients. At the end of the third month, both groups showed highly significant improvement ( $\mathit{p}\mathrm{<}0.01$ ) in VAS and PT (but not ROM). There was no statistical difference in none of parameters between EMS and TENS groups in any time ( $\mathit{p}\mathrm{>}0.05$ ).

In conclusion, TENS seem to be more effective immediately after treatment but in long term evaluation there is no significant superiority of two electrotherapy techniques on each other.