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.
Repetitive magnetic stimulation: a novel therapeutic approach for myofascial pain syndrome.
The aim of this study was to evaluate the short, medium and long-term effects of peripheral repetitive magnetic stimulation (rMS) on myofascial pain compared with transcutaneous electrical nerve stimulation (TENS).Fifty-three subjects with myofascial trigger points (TPs) at the level of the superior trapezius muscle were allocated randomly to three groups. The first group (n=17) was treated with rMS, the second (n=18) with TENS and the third (n=18) received a placebo treatment. Each treatment consisted of ten daily 20-minute sessions. Patients were evaluated before and immediately following treatment, and at one and three months after the end of treatment. Outcome measures were: the "neck pain and disability visual analogue scale" (NPDVAS), an algometric evaluation of pain, an evaluation of the TP characteristics, and the range of cervical bending and rotation contralateral to the affected trapezius muscle. At the end of treatment, the rMS group showed a significant improvement in the NPDVAS, algometry, TP characteristics, and cervical contralateral rotation. This improvement also persisted at one and three months post-therapy. After treatment, the TENS group showed significant improvement in the same outcome measures except for algometry. At the one month follow-up visit, this improvement had returned to non significant levels in all outcome measures with the exception of NPDVAS. No significant effect of TENS was seen at the three-month follow-up visit. The placebo group showed no significant improvement in any measure. Our results strongly suggest that at medium and longer term intervals peripheral rMS may be more effective than TENS for the treatment of myofascial pain.