How many electrodes do most electrotherapy modalities typically require?

Most electrotherapy modalities typically require two electrodes to function effectively. This is because one electrode serves as the positive pole (anode) while the other acts as the negative pole (cathode). The dual electrode system allows for the necessary flow of electrical current between the two points, facilitating the desired treatment effects such as muscle stimulation, pain relief, or increased circulation.

Using two electrodes helps establish a closed circuit, which is essential for the safe and effective delivery of electrotherapy. With only one electrode, you would not be able to create a circuit that allows current to flow and produce therapeutic effects. Although modalities may use additional electrodes in some advanced applications or for specific therapeutic purposes, the fundamental operation of most common electrotherapy modalities is based on a two-electrode system.