Image by Gundula Vogel from Pixabay

Most of us think of ultrasound only as an imaging technique, most often in pregnancy. However, ultrasound therapy has been used as a therapeutic technique for various musculoskeletal conditions for decades. It works by creating vibrations that then translate into sound waves, though not at a frequency we can hear. Our high protein tissues absorb those mechanical waves to a greater degree than tissues with higher water content.

How Ultrasound Therapy Works

The amplitude of the sound wave used determines the intensity and to some extent the mechanism of the treatment. 

High amplitude “shock wave” therapy is used for things like lithotripsy for kidney stones, and it produces more heating effects, and cavitation, in which tiny gas bubbles produced by the ultrasound itself quickly expand and contract, which has a loosening effect. 

Therapeutic ultrasound for tissue healing is low amplitude. Thermal and cavitation effects will still be present to some degree at lower intensity, but at that amplitude, these effects are minimal. So is the rest just a placebo effect (as many of the articles I found tend to speculate), or is there another mechanism at play here?

A Speculative Detour: Exclusion Zone (EZ) Water

One fascinating theory I came across comes from “The Fourth Phase of Water,” by Gerald Pollack (which, incidentally, sheds some light on the potential reason why homeopathy works, as well.) If I can attempt to consolidate his unique argument into a nutshell, it’s that when water comes in contact with a hydrophilic (generally negatively charged) surface, the water molecules next to said surface arrange themselves in a lattice-like honeycomb structure, producing an “exclusion zone” in which almost no solutes or charged particles can penetrate. The exclusion zone itself is negatively charged, while the rest of the water beyond it takes on a relative positive charge. 

This is essentially a battery. Our bodies largely run on charge differentials, too: muscle contraction or the firing of nerves is dependent upon the release of charged particles from one compartment to another. Since most of the surfaces inside our cells are charged (meaning they are hydrophilic), the fluid inside our cells near it will thus become exclusion zone water. The exclusion zone itself is what maintains the separation of charges, thus storing the potential energy for future use. 

Pollack argues that growth of the exclusion zone “charges” the battery–and if it is a battery, of course it does, because a greater exclusion zone means a greater charge differential. Pollack then presents a series of experiments demonstrating that two things in particular seem to charge that battery, or promote growth of an exclusion zone. One of these is light (particularly infrared—another great reason to consider infrared therapy, or just spend time in sunlight). 

The other is ultrasound. Pollack’s experiments showed that while initially, the EZ narrowed in response to ultrasound, a rebound significant expansion occurred immediately afterwards, to five or six times the initial EZ size. (This sounds like a hormetic effect to me—and I’m beginning to realize most of my favorite therapies operate on this principle!) 

So I wonder if the reason why ultrasound therapy might be effective could be due to its EZ growth effects, creating greater charge separation in the tissue in question, which can then be converted to various kinds of work—such as tissue repair. 

What the Studies Show

Ultrasound therapy has been shown to be effective for a number of different musculoskeletal conditions. These include: 

The Upshot

Low-intensity ultrasound therapy is a non-invasive, low-risk approach to stimulate tissue healing and repair, primarily for musculoskeletal conditions. We now offer it at Nature Cure Family Health!