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.
A randomized trial of chiropractic manipulation and mobilization for patients with neck pain: clinical outcomes from the UCLA neck-pain study.
This study compared the relative effectiveness of cervical spine manipulation and mobilization for neck pain.
                Neck-pain patients were randomized to the following conditions: manipulation with or without heat, manipulation with or without electrical muscle stimulation, mobilization with or without heat, and mobilization with or without electrical muscle stimulation.
                Of 960 eligible patients, 336 enrolled in the study. Mean reductions in pain and disability were similar in the manipulation and mobilization groups through 6 months.
                Cervical spine manipulation and mobilization yield comparable clinical outcomes.