Jan. 27, 2010 -- Running barefoot causes less collision force to the feet than running in cushioned shoes, a new study says.

Researchers reporting in the Jan. 28 issue of the journal Nature show that runners who run without shoes usually land on the balls of their feet, or sometimes flat-footed, compared to runners in shoes, who tend to land on their heels first.

Cushioned running shoes, which date back only to the 1970s, may seem comfortable but may actually contribute to foot injuries, say Daniel Lieberman, PhD, professor of human evolutionary biology at Harvard University, and colleagues.

The scientists, using motion and force analyses, showed that barefoot runners who strike on the fore-foot (land on the balls of their feet) generate smaller collision forces than shod rear-foot strikers.

The researchers say that although there are anecdotal reports of reduced injuries in barefoot populations, more work is needed to test their view that either barefoot runners or those with minimal footwear (such as sandals or moccasins) have reduced injury rates.