Therapeutic Ultrasound


You may have been offered an ultrasound treatment during your physiotherapy or chiropractic session, and you probably accepted it without too much thought. You gave in to the cold dollop of blue gel and the circular rhythm of the wand for a couple minutes, then packed up and got going with your life. You may have not even felt anything! So what exactly is ultrasound, and how does it help?

Ultrasound is a device that sends ultrasonic (high frequency sound) waves through your skin into the tissues below. Frequencies of the wave can be adjusted depending on how deep the waves must penetrate.

There are two effects of therapeutic ultrasound: non-thermal and thermal. Non-thermally, the ultrasound works to break up scar tissue by using the vibration from the wave. This is called cavitation. A mass of scar tissue experiences a pressure change with the sound wave, causing it to break up into progressively smaller masses until finally disappearing for good. For example, lithotripsy is a procedure in which gall and kidney stones are broken up by using ultrasound.


The waves are absorbed by structures beneath the skin – such as ligaments, tendons, fascia, and even scar tissue. The absorption creates a thermal effect as the waves vibrate throughout the structure. This increases blood flow into the area to promote faster recovery. Blood vessels dilate due to the heat so that swelling and edema flush out, reducing pain. Fresh blood full of oxygen and nutrients can now flow through with ease to aid in rebuilding tissue.


Our practitioners find that ultrasound used in combination with other therapies—for example, Active Release Technique or manual therapy—is more effective than simply using ultrasound on its own. Often, our chiropractors do this with Graston. The ultrasound acts as a warm-up; it increases temperature and begins the scar tissue breakdown process. Then, the Graston tool can get in to further break down more efficiently.


Ultrasound is more effective than a heat pad because, as you may have experienced, the skin is in direct contact and may become unbearably hot; meanwhile, the deeper structures receive less heat. Ultrasound can be adjusted to actually reach its target without causing discomfort—or even any change in sensation—to the skin.


There are a number of other types of ultrasound used in the medical field as well. Perhaps the best-known type is for diagnostic purposes. The sound waves create an image of internal structures like babies or injured tissue. Shockwave therapy is similar to the cavitation effect of the ultrasound therapy. Its difference is in the strength of wave—shockwave therapy is at a higher intensity, which affect the tissue composition at a cellular level in a different way. Even deep structures such as bones can be stimulated to increase cell production and bone density.