**4. Technique**

Direct bath method

The treatment area should be clear and flat. Then, the coupling medium like aquasonic gel should be applied to prevent excess air between the skin and treatment head and to allow the ultrasonic beam to pass through the body tissues. The treatment head is moved in rhythmic direction in order to avoid concentration at one point.

Parameters


Thermal effects


Nonthermal effects

• **Cavitation** is the oscillatory activity of highly compressible bodies within the tissues such as gas- or vapour-filled voids.

It may be **stable** or **unstable** cavitation.

