Instrumental therapy 
The electrotherapy (also known as instrumental therapy) uses the biological effects achieved through the electricity for therapeutic purposes and consists of electrical currents circulate in the body part, being careful to choose them with certain characteristics suitable for the purpose to be achieved. 
You can exploit the current continues being able in this case aggregating properties of certain drugs that can be transmitted through the same current, in the part to be treated (iontophoresis) or variable current (current eccitomotorie), both with thermal effect that with analgesic effect (current diadynamic and TENS).