Few studies back promises made by makers of so-called 'functional footwear'

By Kaye Spector

Health and Medical Reporter, The Plain Dealer

It sounds so easy.

All you have to do is put on a pair of shoes, and by simply going about your daily business -- grocery shopping, standing in line at the bank or picking up the dry cleaning -- you get great-looking legs.

That's the promise of "functional footwear" such as MBTs, FitFlops, Reebok's EasyTone sneakers and Skechers' Shape Up shoes.

The manufacturers claim that instability built into the shoes makes it harder to maintain balance and stand erect, forcing the wearer to use and develop muscles that aren't engaged with regular shoes. The footwear also is supposed to reduce stress on the joints and the back.

MBTs, the granddaddy of functional shoes, are made by Switzerland-based Masai Group International Ltd. and have been available in the United States since 2005.

This year, Reebok and Skechers came out with their own less-expensive versions, promising shapelier calves and a tighter rear end without the wearer going anywhere near a gym.

(MBTs cost from $240 to $390, while Reebok and Skechers cost around $100.)

So are the claims all marketing? Or do they work?

In theory, they could work, says Dr. Amanda Weiss Kelly, director of pediatric sports medicine at Rainbow Babies & Children's Hospitals.

But there are few rigorous, peer-reviewed scientific studies to prove it, she says.

One such study shows the MBTs can improve function and reduce knee and lower back pain for patients with knee osteoarthritis.

"For someone with arthritis, these shoes might be worth a try," Weiss Kelly says. "Some research supports this. But you have to be up and moving."

Another showed that developmentally delayed children with motor difficulties who wore the MBTs for two hours a day improved their balance.

"Theoretically speaking, by activating different muscles, you could end up firming and toning the muscles," Weiss Kelly says. "But nobody has done a controlled medical study on it."

The most important thing the shoes might do, Weiss Kelly says, is encourage their owners to walk more.

"Wearing these while sitting at a desk is not going to expand your calorie expenditure," she says. "I don't care what kind of shoes you wear, you have to exercise. I would just be thrilled if we could get people up and walking."