Therapeutic ultrasound is a commonly used treatment for a variety of musculoskeletal conditions. Ankle sprains are among the most commonly seen sport-related injuries and proper acute management can significantly improve the rate of healing and return to activity. A major goal during the acute stage of healing is to control pain and inflammation. The delivery of therapeutic ultrasound to an acutely sprained ankle can reduce pain and swelling while facilitating tissue healing.
Therapeutic Ultrasound Defined
Unlike ultrasound that produces an image of something inside the body, therapeutic ultrasound consists of the application of high-frequency mechanical vibrations created by the conversion of electrical energy to sound waves. Therapeutic ultrasound is typically applied at a frequency of either 1 or 3 megahertz, or MHz, depending on the depth of the target tissue. Lower frequency -- 1 MHz -- targets deeper tissue, like a deep thigh muscle, while 3 MHz is absorbed more superficially, like on the Achilles tendon.
Effects of Therapeutic Ultrasound
Therapeutic effects of ultrasound are typically divided into thermal and nonthermal effects. Nonthermal effects are those that are thought to be therapeutic in the acute stages of healing and include increased fluid movement in the area, increased protein synthesis and improved blood flow. These effects lead to reduced pain and swelling, and improved tissue healing. The application is simple, consisting of placing a water-based gel on the skin, and then moving the sound head in small circles over the target area.
Therapeutic Ultrasound for Acute Ankle Sprains
A sprained ankle occurs when ligaments that stabilize the ankle are stretched or torn, resulting in acute pain, swelling and loss of function. Since the ligaments in the ankle are very superficial, your certified athletic trainer, physical therapist or doctor may apply non-thermal, 3 MHz ultrasound over and around the damaged ligaments. Treatment time varies but usually falls between five and 10 minutes per treatment, during which the patient feels nothing more than the movement of the applicator against the skin.
Therapeutic Ultrasound: Is It the Right Treatment?
While there is some controversy in the research regarding the benefits of therapeutic ultrasound for acute ankle sprains, the procedure is generally safe and well tolerated by patients. Make sure to alert your health care provider to any medical conditions you may have that may be contraindications for ultrasound, including metal implants, sensory problems, cancer or circulatory impairments. In many cases, the application of nonthermal ultrasound to an acutely sprained ankle can reduce pain, speed healing and get you back on your way to recovery and return to activity.
- "Rheumatology"; Therapeutic Ultrasound in Soft Tissue Lesions; C.A. Speed; June 2001
- "Journal of Athletic Training"; Non-Thermal Effects of Therapeutic Ultrasound; Lennart Jones; July-Sept. 2002
- The Cochrane Library; Therapeutic Ultrasound for Acute Ankle Sprains; Van der Windt DAWM et al.; 2006
- Archives of Physical Medicine and Rehabilitation; Contraindications for Superficial Heat and Therapeutic Ultrasound; Mitchell Batavia; June 2004