Therapeutic ultrasound is atreatmentcommonly used in physical therapy to provide deep heating to soft tissues in the body.
These tissues include muscles, tendons, joints, and ligaments.
Ultrasound in physical therapy is different than diagnostic ultrasound.
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With the latter, healthcare providers use ultrasound to see the inside of the body.
For example, diagnostic ultrasound lets healthcare providers check on a fetus during pregnancy.
This article explains how therapeutic ultrasound works and when it’s used.
What Is Therapeutic Ultrasound?
Therapeutic ultrasound is used to heat tissues and introduce energy into the body.
Deep Heating Effects
Ultrasoundcan provide deep heating to soft tissue structures in the body.
Non-Thermal Effects (Cavitation)
In addition to heat, ultrasound introduces energy into the body.
This energy causes microscopic gas bubbles around your tissues to expand and contract rapidly, a process called cavitation.
How Does Ultrasound Work?
Inside your physical therapist’s ultrasound unit is a small crystal.
These waves emit from the ultrasound sound head as ultrasound waves.
During treatment, the ultrasound wave then enters into your injured tissues.
This exposure to ultrasonic waves increases blood flow and cavitation, leading to the theorized benefits of the treatment.
When Is It Used?
PTs may use therapeutic ultrasound to treat some injuries and chronic pain.
Injuries
Usually, PTs treat orthopedic (musculoskeletal) injuries with ultrasound.
In addition, they sometimes use it for chronic pain.
What to Expect
Ultrasound uses a machine that has an ultrasound transducer (sound head).
If this occurs, tell your physical therapist right away.
In addition, they may use different parameters during various stages of healing.
(The ultrasound gel and sound head may harbor bacteria that can enter the wound.)
This process is calledphonophoresis.
Your PT may use various prefs or different software methods depending on your situation.
Contraindications
There are some instances where you should not use ultrasound at all.
These contraindications to ultrasound may include:
Does Evidence Support Its Use?
Studies have been mixed as to whether or not ultrasound offers benefit to the overall outcome of physical therapy.
Is It Right For You?
Some argue that ultrasound can harm your physical therapy by needlessly prolonging your care.
Some people may suggest that the benefit of ultrasound for chronic pain is due to the placebo effect.
But, if it gives you relief, then it is the proper treatment for you.
Ultrasound is a passive treatment.
Exercise and active involvement should always be the main components of your rehab program.
Summary
Therapeutic ultrasound is different from diagnostic ultrasound.
PTs use it to treat some injuries and chronic pain.
Evidence is mixed on the purported benefits of therapeutic ultrasound.
2013;19:661-667. doi:10.12659/MSM.889145
Brennen CE.Cavitation in medicine.Interface Focus.
2018;48(11):847-855. doi:10.2519/jospt.2018.8110
American Academy of Physical Medicine and Rehabilitation.Therapeutic modalities.
2022;34(1):2-8. doi:10.1097/PEP.0000000000000846
National Library of Medicine, National Institutes of Health.Ultrasound therapy.
2014;93(5):405-12. doi:10.1097/PHM.0000000000000033
