Effect of magnesium sulfate iontophoresis on myofascial trigger points in the upper fibres of the trapezius

OBJECTIVE: To investigate the immediate and post-treatment effect of magnesium sulfate (MgSO4) iontophoresis on myofascial trigger points (MTrPs) in the upper fibres of the trapezius muscle. METHOD: Sixty participants (41 women and 19 men, aged 19–24 years) with active MTrPs on the dominant upper fibres of trapezius were enrolled in this study. They were randomly divided into 2 equivalent groups: the intervention and the control group. The intervention group (iontophoresis group; n = 30) was treated with MgSO4 iontophoresis on the upper fibres of the trapezius twice a week for four weeks, and the control group (direct current group; n = 30) received direct current (without medication) in the upper fibres of the trapezius twice a week for four weeks. The outcome measures were: pain intensity, pain threshold, neck range of motion, and neck function The participants were assessed before treatment, immediately after the first session, and finally after treatment. RESULTS: The differences within and between groups were measured using a mixed design, multivariate analysis of variance (MANOVA). The within- and between-group analysis of all outcome measures in both groups revealed significant differences in favour of the intervention group (p < 0.05). CONCLUSION: MgSO4 iontophoresis is effective in improving pain level, neck ROM, and neck function immediately after the first session and causes more significant improvement after treatment in subjects with active MTrPs on the dominant upper fiber of trapezius.