Therapeutic ultrasound is a treatment commonly used in physical therapy. It is used to provide deep heating to soft tissues in the body. These tissues include muscles, tendons, joints, and ligaments. Ultrasound in physical therapy is not to be confused with diagnostic ultrasound, which is an ultrasound that is used to see the inside of the body, such as checking on a fetus during pregnancy.
Deep heating tendons, muscles or ligaments increases circulation to those tissues, which is thought to help the healing process. Increasing tissue temperature with ultrasound is also used to help decrease pain. Deep heating can be used to increase the “stretchiness” of muscles and tendons that may be tight.
Non-thermal effects of ultrasound allow energy to be introduced into the body. This energy causes microscopic gas bubbles around your tissues to expand and contract rapidly, a process called cavitation. It is theorized that the expansion and contraction of these bubbles help speed cellular processes and improves healing of injured tissue. Two types of cavitation include stable and unstable cavitation. Stable cavitation is desired when your physical therapist is applying ultrasound to your body. Unstable cavitation can be dangerous to your body’s tissues, and your physical therapist will ensure that this does not occur during the application of ultrasound.