Diathermy is a form of therapy that uses a deep heating in the tissues to aid the body. The diathermy definition is a literal translation of its name, which means “heating through”. The effects of a high-frequency alternating current on tissues were originally found by Nikola Tesla, who also proposed that there could be medical uses of this heat irradiation.1 The three main types performed by physical therapists are ultrasound, microwave, and shortwave. All three types can only reach about two inches below the surface of the skin. The machine does not touch the patient to generate heat; it sends out waves of energy to target specific tissues. Microwave diathermy yields better results on tissues that are closer to the skin because the microwaves are unable to reach the deeper muscles. The microwaves can warm the shallow tissues evenly without creating excessive heat in the skin. The sound waves from the ultrasound type can penetrate deeper than microwaves. The generation of heat is caused by the sound wave vibration of the tissues.2 Short wave diathermy is performed with the use of electrode pads. A towel is usually used as a barrier between the body and the electrode, and another electrode is placed on the opposite side of the affected body part. The electrode pads and towels create a sandwich where the targeted part of the body is the center. Radio waves bounce between the two electrodes, creating heat in the body tissue between the pads. The electrical current frequencies are at a level that does “not stimulate motor or sensory nerves” or cause muscle contraction.3
Effects of Diathermy
Diathermy uses heat to warm tissues that are causing pain. Arthritis, back pain, fibromyalgia, tendonitis, bursitis, neuralgia, muscle spasms, sprains, and strains are some of the conditions this treatment is meant to address. The heat increases the flow of blood around the affected areas to accelerate healing. The heat is also supposed to improve mobility during the healing process. After the treatment, the patient might gain some flexibility in the treated area. This might make participation in physical therapy more comfortable for a longer period of time, which is important for healing and strengthening some medical conditions. While there is “not a lot of evidence to prove that diathermy is the most effective treatment for these conditions”, the therapy may provide some relief. Patients with metal devices in their body, such as bone pins, dental fillings, a pacemaker, or metal sutures, might choose to the forgo microwave and shortwave diathermy for the ultrasound type. The treatment could cause extreme heat in the metal devices, leading to burns near the implant. The patient’s body becomes a part of an electrical field during the therapy, so touching a bare, metal object is discouraged because the skin can be shocked or burned. Children with open growth plates should not receive diathermic therapy near those sensitive areas. Any other medical conditions or implants should be discussed with the doctor prior to receiving this therapy to find out if the patient is at any risk.4
How Does a Surgeon Use Diathermy?
Diathermy has a variety of uses in a surgical setting. It is utilized differently during a surgery compared to its purpose for physical therapy. When used in specific ways by a professional, it can cut through cells and cell walls and constrict tissue cells to increase rate of blood coagulation. Even using a high frequency electrical current, this treatment does not affect the nervous system and muscles. It is a very precise method of cell manipulation and reparation that does not affect the major systems.5 There are two types of diathermy used in surgery: monopolar and bipolar. With the monopolar type, one electrode is placed near the target tissue while the other is placed elsewhere on the body, often around the leg or lower back. The electrodes in bipolar type are mounted on the same device, which means that the electrical current only passes through the targeted tissue and nowhere else in the body. Bipolar diathermy is used for microsurgery as well as patients that have a cardiac pacemaker because it is so precise. Surgical diathermy is also known as electrosurgery or electrocautery.
How Chiropractic Care Can Help
Some chiropractors also use diathermy in their practice as a treatment modality. It is said that “microwave…is typically the weakest of the three forms… shortwave or ultrasonic…address musculoskeletal injuries that are located 2 to 4 cm below a person’s subcutaneous tissue layer”.7 Patients will feel “pleasantly warm” in the area of treatment.8 Chiropractic care can also treat fibromyalgia, back pain, muscle spasms, sprains, and strains. The manipulation of the spine, neck, and other areas of the body can realign and relieve pressure that could be causing pain. A chiropractor may also recommend a physical therapist and some exercises that the patient can perform at home to continue the maintenance of pain relief. Chiropractors have many tools that they utilize to help the patient, and these tools are less invasive.9