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Does Ultrasound Really Work?


Updated June 05, 2014

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Doctor using sonogram on patient
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If you have an injury such as bursitis, tendonitis, or arthritis you may require physical therapy to help decrease pain and improve function. Your physical therapist may choose to apply therapeutic ultrasound to your injured body part as part of your rehabilitation program.

Therapeutic ultrasound is a treatment that has been used in physical therapy clinics for over 50 years. It provides heat to injured body parts that lie deep within your body that are not able to be heated with a standard hot pack alone. Ultrasound is also thought to improve cellular function by making microscopic gas bubbles near your injury expand and contract rapidly. This expansion and contraction is thought to speed up the healing process in your injured body part.

But does ultrasound really work? Does ultrasound really provide heat to the deep tissues in your body, and does this heating have a positive effect on helping your injury heal better or faster?


A review of published studies about ultrasound indicates that it certainly does heat your body parts when applied correctly. It also heats parts of your body that are deep and located outside of the reach of standard hot packs. So if you have an injury and your physical therapist feels that heat may be required to help your condition, ultrasound is a good choice to use.

Speed of Healing

Studies about using ultrasound to help speed healing are not so positive. There are many studies that compare ultrasound use to sham (fake) ultrasound. These studies indicate that people who receive ultrasound for an injury do not have a speedier, healthier recovery or a better outcome.

For example, in a study on the use of ultrasound for knee arthritis, some of the study participants received the ultrasound treatment, while other study participants received sham ultrasound. There were no differences in the recovery of patients in either group.

There is one positive study on the use of ultrasound in the treatment of shoulder pain. A 2001 review of studies for treatments for shoulder pain gave ultrasound a grade of “A” (benefit demonstrated) for the use of ultrasound in the treatment of one specific shoulder condition. This was for the treatment of calcific tendinitis in the shoulder. This painful condition limits shoulder range of motion and causes pain when moving your arm.

Can Ultrasound Hurt?

Ultrasound is a pretty safe and innocuous treatment in physical therapy. There are some instances where ultrasound should absolutely not be used, such as over body parts with cancer and in young children, but for the most part, it can be used safely to heat injured parts of your body.

Since many studies show that ultrasound offers very little to help speed healing in your injured body part, some physical therapists feel that ultrasound can “hurt” by making you feel like you need it to get better. Treatments where you are not actively involved in your care may make you feel like you have very little control over the management of your injury. This puts responsibility for your care in your physical therapist’s hands and not your own.

The Placebo Effect

Many physical therapists continue to use ultrasound and many feel that it adds positive outcomes in the treatment of many conditions. But is it really the placebo effect?

The placebo effect is a phenomenon where you perceive improvement in your condition simply because something is being done to you. Your physical therapist tells you that ultrasound treatments can make you better, and therefore you start to feel better after receiving the treatments.

If your condition improves because of the placebo effect, that is fine. But some professionals argue that using the placebo effect in the treatment of conditions is unethical.

Bottom Line

In general, ultrasound is a safe treatment that has been used in physical therapy for many years. It provides heat to deep structures in the body, and it is thought that this heat helps improve that way that your body heals.

Studies may not really support the use of ultrasound in physical therapy. Still, it is commonly used and you may come across it if you go to physical therapy, so you should have some idea about what it is and what it can (and can’t) do.

If you do receive ultrasound, you should also be actively involved in your physical therapy plan of care. You should make sure that your physical therapist helps you understand your condition and that he or she offers you strategies that you can apply to help improve your condition independently.


Falconer, J. etal. Effect of ultrasound on mobility in osteoarthritis of the knee. A randomized clinical trial. Arthritis and Rheumatism. 1992 Mar; 5(1): 29-35.

Prentice, W. (1998) Therapeutic modalities for allied health professionals. New York: Mcgraw-Hill.

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