They are the newest twist on the oldest walking technology on Earth: feet.
"It is like wearing little hobbit feet," said 42-year-old Hollywood screenwriter Matthew Sand, who wears his barefoot shoes to walk his pit bull. "It feels like walking barefoot across the grass when you were a kid, but also high-tech and cool. It is both the future and the past wrapped up with me and my toes."
The explosion in funky footwear that promises stronger muscles and better posture has some wondering whether these barefoot shoes are merely a passing fad — the Earth shoe of the 21st century — or something more lasting in the ever-expanding sports-shoe continuum.
"More than a trend, they are going to be a new category of shoe for workout enthusiasts," said Linda Sparling, general manager for FrontRunners, a longtime fitness retailer in Brentwood. "But yes, when they first came in, we had them sitting with the Earth shoes."
The most distinctive of the barefoot shoes is the FiveFingers, the individual-toed bootie with a 2-millimeter rubber sole that was dreamed up by Vibram, the renowned Italian company best known for making high-performance rubber soles for hiking boots. The patented design was introduced in 2006 and marketed for kayaking and sailing. But the shoes became a hit among barefoot runners.
The privately held company doesn't release exact sales figures, but Vibram is on track to sell 10 times more barefoot shoes this year than it did in 2009, said Georgia Shaw, marketing director for Vibram USA.
The success of FiveFingers has spawned a new generation of barefoot shoes that are less weird-looking — they lack individual slots for each toe — but are still light and low to the ground:
• New Balance just released the Minimus collection, with shoes for trail, road and life, accompanied by the motto "" (that's roughly "less equals more" for the mathematically challenged).
• Merrell, which makes hiking shoes and sandals, introduced its Barefoot Collection in March with shoes that promise to strengthen, realign and stimulate your feet.
• Fila's Skele-toes minimalist shoes evoke the original FiveFingers, but they have only four toe compartments (the last two toes slide in together). Fila promotes them "for just about everywhere" but specifically not for running.
Those who believe in barefoot shoes contend the footwear uses the body's natural biomechanics to strengthen the calf, core and foot muscles, change one's gait and improve posture. By taking the foot out of the "cast" of a regular shoe, the barefoot shoes improve the range of motion of ankles and feet. Unshielded by the thick, padded soles of running shoes, receptors in the feet receive information about surfaces and slopes, training the body to respond with balance and agility. And by eliminating the heel lift, body weight is distributed across the entire foot, promoting spinal alignment.
"I do not think it is just a flash in the pan," says Dr. Peter Langer, a podiatrist in Minneapolis and a self-described "shoe geek" who spent years working in a running shoe store. "When you put on unconventional footwear, you feel something decidedly different than a normal shoe. You realize how much sensory information you miss out on when you are wearing cushioned athletic shoes."
Putting on toe shoes requires practice. You have to spread your toes wide, wiggle in the big toe, and guide the rest of the toes in one at a time. But once you are in, they feel great, devotees say.
Wearing the shoes is like being barefoot — on steroids. With your toes pried apart, you feel like you can grip the floor like a monkey. The thin rubber sole feels more springy and safe than skin, eliminating the fear of a puncture wound or a burn. After you put them on, you realize you have never been completely relaxed when walking barefoot.
Few dispute that the trend took off with Christopher McDougall's bestselling 2009 book, "Born to Run: A Hidden Tribe, Superathletes, and the Greatest Race the World Has Never Seen." In the book, McDougall posits that running shoes may be the most destructive force to ever hit the human foot. He quotes a Harvard professor of biological anthropology who says foot and knee injuries are often caused by shoes that make our feet weak. He talks about Kalahari Bushmen who run barefoot for hours in the desert chasing antelope until the animals die.
MacDougall endorsed barefoot running — not barefoot shoes — but it didn't take long for people to figure out that FiveFingers and its offspring could make barefoot running more palatable. The shoes developed a cult-like following among MacDougall's die-hard fans, and their popularity spread by word of mouth, attracting workout fanatics looking for something different, early adopters looking for the next cool thing and those for whom returning to a simpler, more natural state of things is both a quest and a lifestyle.
Leisure Trends Group, a market research firm in Boulder, Colo., estimates that in the first three months of this year, enthusiasts bought 365,000 pairs of minimalist shoes in specialty stores devoted to running and outdoor sports. (That figure doesn't include sales by mass merchants, department stores or regular shoe stores.)