Mechanical vibrations at increasing frequencies is known as sound energy. Beyond the normal human hearing range (16Hz to 20,000Hz) this mechanical vibration is called ultrasound. The frequencies used in this therapy are typically 1.0 and 3.0 MHz. 1MHz = 1 million cycles per second.
As the energy within the sound wave passes through tissue energy is transferred to the tissue. This extra energy helps with healing.
Ultrasound on certain tissues help to make the repair phase of tissue healing as efficient as possible, and thus have a promotional effect on the whole healing cascade. It is also good for tissues that are showing little signs of healing as the extra energy ultrasound gives help to promote healing.
As well as promoting healing it also helps to stimulate new tissue formation and changes the orientation of the fibres, enhancing the tissue strength and mobility.