Shortwave Diathermy By Ms.B. Nelson

Objectives To explain the physiologic effects of shortwave diathermy Identify the effects of shortwave diathermy Discuss the various clinical applications and indications for using continuous shortwave and pulsed shortwave

What is diathermy ? The application of high- frequency electromagnetic energy that is primarily used to generate heat in body tissues

Diathermy cont’d Diathermy as a therapeutic agent may be classified as 2 distinct modalities , namely shortwave and microwave diathermy

Shortwave diathermy (SWD) SWD may be CONTINUOUS or PULSED

Effects of SWD There are two main effects of SWD : Thermal Non thermal

Thermal effects Increase in tissue temperature in the deeper tissues. The increase in tissue temperature results in : Increase vasodilation Increase conduction velocity and elevation of pain threshold level Increase soft tissue extensibility Increase enzymatic activity

Thermal effects cont’d SWD can heat deeper tissues than superficial thermal modalities SWD heats a larger area than ultrasound

Non Thermal effects Non thermal effects are produced when SWD is PULSED Pulsed shortwave diathermy (PSWD) is created by interrupting the output of continuous shortwave diathermy

Effects of PSWD Increase local circulation Increase oxygenation and nutrition to the tissues

PSWD cont’d PSWD has also been used in the treatment of soft tissue injuries and wounds

Clinical indications- Continuous shortwave (Thermal level) Control of pain Increase the rate of tissue healing Decrease joint stiffness (can be applied in conjunction with stretching) Indicated to achieve clinical benefits of heat in areas such the HIP joint and the spine

Clinical indications- PSWD(non thermal level) Control of pain and oedema Soft tissue healing Symptoms of osteoarthritis

Types of shortwave applicators There are 2 types of shortwave applicators: Inductive coils capacitive plates

Inductive applicators The inductive applicators are made coils through which AC current flows The AC current creates a magnetic field The magnetic field induces eddy currents The eddy currents cause charged particles in the tissues to oscillate The friction caused by the charged particles results in heating of the tissues

Types of inductive applicators There are 2 types of inductive applicators: Cables Drum

Capacitive plates Applicators are made of metal encased in a plastic or carbon electrodes placed between felt pads AC current flows between the 2 plates and through the patient As the current flows charged particles in the tissues oscillate The friction of the particles results in temperature increase

Contraindications Implanted neural stimulators Pregnancy Infection Joint effusion Metal implants NB please read section on contraindication and precautions

Application technique Read application technique on page 395

Documentation Area of the body Frequency range Power setting Pulse rate time