Ultrasound is a therapeutic modality that has been used since the 1940s. Ultrasound is applied using a round-headed wand or probe that is put in direct contact with the patient’s skin. A gel is used on all surfaces of the head in order to reduce friction and assist in the transmission of the ultrasonic waves. Therapeutic ultrasound is in the frequency range of about 0.8-3.0 MHz.

The sound waves produced by the ultrasound machine pass through the skin and cause a vibration of the local tissues. This vibration can cause a deep heating locally though usually no sensation of heat will be felt by the patient. Ultrasound can produce many effects other than just the potential heating effect. It has been shown to cause increases in tissue relaxation, local blood flow, and scar tissue breakdown. The effect of the increase in local blood flow can be used to help reduce local swelling and chronic inflammation, and, according to some studies, promote bone fracture healing. The intensity or power density of the ultrasound can be adjusted depending on the desired effect. Ultrasound can also be used to achieve phonophoresis. This is a non-invasive way of administering medications to tissues below the skin; perfect for patients who are uncomfortable with injections. With this technique, the ultrasonic energy forces the medication through the skin. Cortisone, used to reduce inflammation, is one of the more commonly used substances delivered in this way.

A typical ultrasound treatment will take approximately 5 minutes depending on the size of the area being treated. During the treatment the head of the ultrasound probe is kept in constant motion. When kept in constant motion, the patient should feel no discomfort at all.