Ultrasound
Ultrasound (US) is a form of mechanical energy (not electrical), and therefore, strictly speaking, not really electrotherapy at all, but does fall into the Electro Physical Agents grouping. Mechanical vibration at increasing frequencies is known as Sound Energy. The normal human sound range is from 16 Hz to something approaching 15-20,000 Hz (in children and young adults). Beyond this upper limit, the mechanical vibration is known as ultrasound. The frequencies used in therapy are typically between 1.0 and 3.0 MHz (1 MHz = 1 million cycles per second).
One of the therapeutic effects for which ultrasound has been used is in relation to tissue healing. It is suggested that the application of US to injured tissues will, amongst other things, speed the rate of healing & enhance the quality of the repair. The following information is intended to provide a summary of some of the essential research in this field together with some possible mechanisms through which US treatments may achieve these changes. It is not intended to be a complete explanation of these phenomena or a comprehensive review of the current literature. It may, none the less, provide some useful basic information for clinical application.
