Diathermy refers to the use of high-frequency electromagnetic waves (greater than 10 MHz) as therapeutic stimuli. Shortwave diathermy uses waves of 13, 27, or 45 MHz, while microthermy uses waves of up to 2450 MHz in frequency. Both forms of diathermy generate heat in deep muscle tissue, although microthermy is believed to be absorbed more by superficial fatty issue. The patient is placed between the electrodes, and the power level is adjusted until the patient reaches resonance (as determined by automated measurement systems) with a pre-established heating level. Each diathermy session lasts 10-30 minutes, depending on the size of the target area. The heat generated by diathermy improve blood circulation, relax muscular tension and promote drainage in the target areas.

Electrotherapy is the use of electrical energy in the treatment of impairments of health and a conditions of abnormal functioning. In medicine, the term electrotherapy can apply to a variety of treatments, including the use of direct current in cardioversion and the use of electrical devices such as deep brain stimulators for neurological disease. The term has also been applied specifically to the use of electrical current to speed wound healing. Electrotherapy is used for a variety of needs among which: relaxation of muscle spasms, prevention and retardation of disuse atrophy, increase of local blood circulation; muscle rehabilitation and reeducation; maintaining and increasing range of motion; management of chronic and intractable pain, post traumatic acute pain, post surgical acute pain, immediate post-surgical stimulation of muscles to prevent venous thrombosis, wound healing and drug delivery.