New barefoot shoe for elite runners

Tread carefully with Nike’s new ‘barefoot’ shoe.

The new Nike Free running shoes, designed to mimic the feel of running barefoot, are a bit like nude pantyhose. Why bother?

For starters, most of us would rather not subject our tender feet to shards of broken glass, rusty nails, gum and other nasty objects found in the street. Then there are the elements: Gooey asphalt and icy paths are hardly barefoot-friendly conditions, and the shoes offer a measure of protection.

Shoeless training has its advocates, including the Stanford University track team, which inspired Nike product developers. The human foot has about 20 muscles that strengthen and react when they hit the ground. Some believe that when bound in shoes, the unused muscles can weaken, causing injuries and hampering performance.

The $85 Nike Free, a slipperlike trainer, is marketed as a tool to work out these lazy muscles. Endorsed by football star Tom Brady, runner Paula Radcliff and six-time Tour de France champion Lance Armstrong, it even comes with a suggested training program.

As with any regimen, however, start slowly. The shoe, which Nike says moves and bends like the human foot, “is best used as a supplement” to regular athletic footwear, said Tobie Hatfield, Nike’s senior engineer for advanced products.

Elite athletes, who have naturally good bio-mechanics, will be the ones who can use the flexible shoe without getting injuries such as plantar fasciitis or tendinitis, said Dr. Stephen Weinberg, a podiatric surgeon and the medical director of the Chicago Accenture Triathlon.

For the rest of us, heavy use will “probably result in any one of a number of injuries long before the small intrinsic muscles of the feet (the stabilizers) get stronger or the lower leg muscles adapt to the stress of the increased range of motion of the unrestrained foot,” Weinberg said.

“It’s going to be a short-lived concept that runners will walk around in, probably as an alternative to a sandal,” said Weinberg, who expects to see the Free used as a fashion statement rather than a training aid.