When people with diabetes get foot ulcers, they can often avoid infection and surgery by staying off the foot completely, or by using protective devices like casts or braces. But there’s a lesser known aid that a growing body of research suggests may also speed healing: shockwave therapy.

The most recent study on the subject indicates that shock waves do better than hyperbaric oxygen therapy, which is also sometimes used for foot ulcers. Both of these treatments are meant to increase oxygen delivery to speed healing. Shockwave therapy sends high-energy sound waves directly to an affected area to encourage blood flow, while hyperbaric therapy delivers pure oxygen to the entire body at higher-than-normal atmospheric pressures in a sealed chamber.

In a small study conducted by researchers at the Chang Gung University College of Medicine in Taiwan, 34 people with diabetes and foot ulcers—ages 33 to 79—underwent shockwave therapy three times over six weeks. Meanwhile, 36 similar people with foot ulcers received 20 90-minute treatments with hyperbaric therapy over four weeks. All participants cleaned the ulcers at home with saline, applied silver sulfadiazine cream, and were told to stay off the foot between treatments.

Ulcers healed or improved in close to 90 percent of patients treated with shockwave therapy, compared with just over 70 percent of patients treated with hyperbaric oxygen therapy.

A couple of caveats: Other research has found higher rates of complete healing than with shockwave and hyperbaric oxygen therapy, when using non-removable casts that ensure users take pressure off ulcerated feet. And previous studies indicate that hyperbaric therapy may only help foot ulcers in patients with peripheral arterial disease. In the Taiwanese study, people had little or no peripheral arterial disease. Speculating on why shockwave therapy had the edge in this study, the researchers suggest it more successfully aided regeneration of ulcerous tissue. They caution, though, that this was a small study sample, so more research on larger samples is needed.

Shockwave therapy is approved for treating heel spurs, tennis elbow, and plantar fasci-itis, but not foot ulcers, in the United States. But the researchers anticipate more research will point to benefits of shockwave therapy, possibly changing its status.

This research was published online, Mar. 7, 2008, in the Journal of Surgical Research.