All electrotherapy devices have certain similarities, such as using battery power to apply current to electrodes. The therapies vary in frequencies, waveforms, and effects, however. These are some of the most commonly used kinds of electrotherapy:
Transcutaneous electrical nerve stimulation (TENS) Percutaneous electrical nerve stimulation (PENS) Electrical muscle stimulation (EMS) Interferential current (IFC) Pulsed electromagnetic field therapy (PEMF) Galvanic stimulation (GS)