Shortwave Diathermy ESAT 3640 Therapeutic Modalities

Diathermy Application of high-frequency electromagnetic energy that is used to generate heat in body tissues Heat produced by resistance of the tissue to the passage of the energy

2 Types 2 types Shortwave Microwave

Physiological Responses to Diathermy – Thermal Effects Primary benefits are those of heat in general Increase of 1°C = reduce mild inflammation and increase metabolism Increase of 2 to 3°C = decreased pain & muscle spasm Increases above 3 to 4 °C = increased tissue extensibility

Physiological Responses to Diathermy – Nonthermal Effects Pulsed diathermy may cause repolarization of damaged cells Corrects cell dysfunction Magnetic fields and Na pumps

Shortwave Diathermy Frequency = MHz Wavelength = 11 m Frequency = MHz Wavelength = 22m

Shortwave Diathermy Generators Output intensity Tuning control Power output meter Specific absorption rate (SAR)

Shortwave Diathermy Electrodes Capacitor Electrodes Air Space Plates Pad Electrodes

Shortwave Diathermy Electrodes Induction Electrodes Cable Electrodes Drum Electrodes

Heat Distribution

Treatment Time 15 minutes – produced vigorous heating of triceps surae minutes is most likely adequate More than 30 minutes can result in circulatory rebound phenomenon

Microwave Diathermy Frequency = 2456 MHz or 915 MHz Shorter wavelength than shortwave diathermy Strong electrical field, small magnetic field

Clinical Applications For Diathermy Muscle strains Contusions Ligament sprains Tendinitis Tenosynovitis Bursitis Joint contractures Myofascial trigger points Osteoarthritis Local relaxation Deceased joint stiffness Increased extensibility of collagen fibers Increased circulation Decrease subacute & chronic pain

Diathermy Treatment Considerations Microwave and miscarriage Stray emissions from microwave Avoid when increased temperature may produce negative or undesired effects Power meter does not indicate energy entering tissue Caution when used over fluid-filled areas or organs

Diathermy Treatment Considerations Toweling to absorb moisture Synthetic materials tends to create vapor barrier allowing accumulation of water Don’t use over pelvic area of females when menstruating, testes of males, pregnancy Caution over boney prominences

Diathermy Treatment Considerations Patient should not come in contact with cables connected to generator Keep other medical devices away Metal chairs/tables not used, metal implants No watches or jewelry Unshielded cardiac pacemakers

Diathermy Treatment Considerations Keep other medical devices away Metal chairs/tables not used, metal implants No watches or jewelry Unshielded cardiac pacemakers

Guidelines for the Safe Use of Diathermy Question patient Position patient Inspect part to be treated Drape w/ toweling as indicated Place electrode drum on treatment area Turn on unit Set pulse duration Set pulse frequency Adjust intensity Set treatment time Press start button Periodically check athlete Timer off = end of treatment = turn all dials to 0 Assess treatment efficacy Record treatment parameters