We cannot make any definite statements on the efficacy and clinical usefulness of electrotherapy modalities for neck pain. Since the quality of evidence is low or very low, we are uncertain about the estimate of the effect. Further research is very likely to change both the estimate of effect and our confidence in the results. Current evidence for PEMF, rMS, and TENS shows that these modalities might be more effective than placebo but not other interventions. Funding bias should be considered, especially in PEMF studies.  Galvanic current, iontophoresis, electric muscle stimulation(EMS), and static magnetic field did not reduce pain or disability. Future trials on these interventions should have larger patient samples and include more precise standardization and description of all treatment characteristics.
Therapeutic effects of peripheral repetitive magnetic stimulation on myofascial pain syndrome.
To evaluate short- and medium-term effects of peripheral repetitive magnetic stimulation (rMS) on myofascial pain.
                Eighteen patients who presented with myofascial trigger points (TPs) at the level of the superior trapezius were separated into two groups according to a restricted randomization scheme. Group 1 (n=9) underwent treatment with rMS that consisted of a total of 10 sessions, each lasting 20min, in which 4000 magnetic stimuli were administered in 5s trains at 20Hz at the TP. Group 2 (n=9) received a placebo treatment that consisted of the application of a non-functioning ultrasound therapy device to the TP. Patients were evaluated before treatment, at the end of treatment, and again 1 week and 1 month after the conclusion of the treatment. Clinical evaluation included parameters for measuring pain levels (VAS, NPDVAS and algometry), the myofascial TP characteristics and the range of cervical movement (ROM).
                The rMS group showed a significant improvement in VAS, NPDVAS, algometry, as well as in the characteristics of the TP after conclusion of treatment. Improvements in the ROM were also present in rotation and controlateral bending. This improvement persisted after 1 month. On the other hand, the placebo group did not show any significant improvement in the tests considered.
                The results of this study show that peripheral rMS may have positive short- and medium-term therapeutic effects on myofascial pain.