Therapeutic ultrasound is a treatment modality commonly used in physical therapy. It is used to provide deep heat 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 or to look at the integrity of soft tissue structures like muscles, ligaments and tendons.
What does therapeutic ultrasound do?
Therapeutic ultrasound is used primarily for two different effects: the deep heating treatment and non-thermal uses.
Deep Heating Effects:
Ultrasound is often used to provide deep heating to soft tissue structures in the body. 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. If you have shoulder pain and have been diagnosed with a frozen shoulder, your physical therapist may use ultrasound to help improve the extensibility of the tissues around your shoulder prior to performing range of motion exercises. This may help improve the ability of your shoulder to stretch.
Non-Thermal Effects (Cavitation):
Ultrasound introduces energy 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.