The Medical Electrode transfers the energy of ionic currents in the body into electrical currents that can be amplified, studied and used to help make diagnoses. Medical electrodes permit surface quantification of internal ionic currents, yielding an ordinarily non-invasive test for a variety of nervous, muscular, ocular, cardiac and other disorders that might otherwise have required surgical means to verify their presence. For instance, muscular exams using electrodes may produce evidence of diminished muscle strength and can discriminate between primary muscle disorders and neurologically-based disorders, in addition to detecting if a muscle is truly weak or seems so due to other reasons. The essential role of the electrode is to provide ideal electrical contact between the patient and the apparatus used to measure or record activity.

Electro muscle stimulator is used for rehabilitation purposes. It has become a mainstream method prescribed by physicians and practiced by specialists for rehabilitation after injury. In this use a muscle atrophied during forced rest following an injury, can be helped to speed up muscle strength gain. Practitioners include physiotherapists and chiropractors.