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  • Writer's pictureCryotherapy Austin Blog

How Does Ultrasound Therapy Help

Updated: Mar 21, 2023

What is the purpose of ultrasound therapy for physical therapy?

Ultrasound therapy is a very common therapeutic modality in which high frequency sound waves undetectable by the human ear (above 20 KHz) are used to penetrate tissue, causing vibration, pulsing, and sometimes deep heating. A handheld probe device with a rounded wand, also called a transducer, is usually used to apply the ultrasound, with adjustable intensity settings depending upon the goal of the session, i.e. higher intensity settings are used for the breakdown of scar tissue.

Aside from heating and vibration effects, the ultrasound can also increase scar tissue breakdown, tissue relaxation, and local blood flow. Additionally, it can be utilized to help with phonophoresis, which enhances the delivery of topically applied drugs.

What is the difference between therapeutic ultrasound and diagnostic ultrasound?

Sometimes ultrasound is used for therapeutic purposes, while other times it’s used for diagnostic reasons. For diagnostic purposes, through the high-frequency ultrasound waves and their reflected sounds/echoes, images of internal body structures are created. For a few examples, expecting parents can observe a developing fetus with an ultrasound, the shape of organs can be assessed in a variety of procedures, and a heart and blood vessels can be examined using ultrasound in the form of an echocardiogram. Abdominal scans, pelvic scans, pregnancy scans, and musculoskeletal scans may be conducted using ultrasound to evaluate various conditions. Sometimes probes are also inserted into the patient’s vagina, rectum, blood vessels, esophagus, etc.,in order to get a clearer view of things during the examination.

Therapeutic ultrasound is similar to the diagnostic type, but no images are produced. The intention of this is to remedy a situation in the body without any incision being made, being entirely non-invasive. It is used to modify or eliminate certain tissues, i.e. dissolving blood clots, heating or moving tissue, delivering medications to an area of the body, etc.

Is ultrasound therapy safe?

Ultrasound therapy is thought to be safe and helpful in the speeding up of healing by applying heat to affected tissues. Lessening of pain, improvement in cellular healing, and increased range of motion/flexibility are all considered possible upsides with ultrasound therapy -- but there is not a great deal of science to prove its efficacy, and in some cases, it should definitely be avoided.

According to Dr. John D. Ratcliffe of NOVA Chiropractic & Rehab Center in Sterling, Virginia, technicians use the acronym PHIMM to establish whether it’s safe for the patient to undergo ultrasound therapy. This acronym spells out:

P: Pregnancy (Is the client pregnant?)

H: Hemorrhaging (Are they hemorrhaging or bleeding?)

I: Infection (Is there an infection present?)

M: Malignancy; Cancer (Is there any malignant cancer present?)

M: Metal (if the patient has any metal in their body, avoid ultrasound as it may heat the metal)

Can ultrasound therapy be harmful?

In addition to the acronym stated above, a more thorough consideration should be given to risks as well. Before anyone receives ultrasound therapy, they should thoroughly understand why it’s being conducted and the therapeutic expectations. The following should be considered as reasons to avoid ultrasound therapy:

Cancer patients

In children or those with bones not yet fully developed

When pregnant *except for the pregnancy ultrasound; therapeutic ultrasound should not be received when pregnant

Anywhere near the eyes

Anywhere near the heart (esp if you have a pacemaker)

Over reproductive organs (testes, ovaries)

In areas with decreased temperature sensation (per injury or otherwise lessened sensation)

Over body parts with total joint replacements (sealant used may be heated/damaged by ultrasound)In anyone with vascular problems (i.e. circulatory issues)

What does ultrasound gel do?

Ultrasound gel performs as a conductive medium in that it reduces air space between the patient’s skin and the transducer, as well as reducing or eliminating static. This is helpful because air creates difficulty for ultrasound waves to travel, so therefore reducing it with the gel allows the sound waves to go directly through to the tissues under the skin, producing a clearer image to work with.

What frequencies are most often used?

1 or 3 MHz frequency are the most often used for therapeutic ultrasound (for diagnostic ultrasound purposes, 5 to 10 MHz are most often used)A 1 MHz frequency travels 1.5 inches into muscle; 6 inches into fat3 mhz does a ⅓ of the depth of a 1 MHz frequency

To determine your duty cycle (percentage of time ultrasound device is “on”):


If the injury is very deep, adjust the intensity accordingly

Acute injury - an injury that just recently happened under 14 days ago (tissue is much more receptive to ultrasound during the acute stage) = duty cycle 10-20%

Sub-acute - Injury occurred 14 days - 6 weeks ago; duty cycle = 50%

Constant - Injury occurred over 6 weeks ago = duty cycle 100%

Does ultrasound therapy really work?

Ultrasound, also known as sonogram, therapy appears to be remarkably lacking in scientific evidence proving its efficacy. Very few studies do prove such claims, such as one that revealed “continuous therapeutic ultrasound can improve force production after contraction-induced muscle injury”, (Forester et al., 1982; Karnes and Burton, 2002), and another that showed that “treatment with pulsed ultrasound can promote satellite cell proliferation but “did not have a significant impact on overall morphologic manifestations of muscle regeneration”. (Rantanen et al., 1999).

Research recently conducted at the University of Michigan seems to show promise in the dissolving of blood clots in pigs via the use of a high intensity ultrasound technique called histotripsy. In this technique, “short, high-intensity pulses of ultrasound to cause clot breakdown.” However, the research has so far only been conducted on pigs, not humans. Still, doctors and technicians seem to continue to use the therapeutic technique per their own experience and preferences -- and many patients find benefits in receiving it in spite of the lack of scientific studies.

If you’re interested in seeing how ultrasound therapy can benefit you, give us a call or stop in anytime we’re open. Our helpful, informed staff will be more than happy to answer any questions you may have and set up an appointment for your first session!

Cryo Body Works

(512) 522-0221

3501 Hyridge Dr

Austin, TX 78759

Mon - Fri 7AM - 8PM

Sat 10AM - 5PM

Sun 12PM - 4PM

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