Three years ago, Jan Hetherington stepped outside her house for a run in her neighborhood, leaving behind her shoes - along with the injuries she believes they caused.

Hetherington, 61, is a barefoot runner. Four days a week, she jogs around her Oakland neighborhood and Lake Merritt, her bare feet slapping the ground. It feels, she said, like "being a child again."

"It's the feeling of being barefoot and having your feet on the ground and that real connection to the ground and the feeling that goes through the whole body," she said.

Hetherington is among a growing number of runners who have traded in their Asics and Nikes for minimalist or no shoes at all, a style popularized by the best-selling 2009 book "Born to Run."

Converts say they've adopted barefoot running to reconnect with the way humans were intended to run, and by doing so are significantly reducing injuries.

But health experts are not so sure. While studies show that barefoot runners' feet hit the ground with less force than those of runners with shoes, they say there is no conclusive proof that it actually results in fewer injuries.

A shoeless runner

The art of natural movement has always interested Hetherington, a self-employed physical activity practitioner. She started competing in marathons in the 1990s, but took a break when she was hit by a car while training in 2000. Before and after the accident, she said her Achilles' heel often felt painful and inflamed.

In 2009, she read Christopher McDougall's "Born to Run," and was intrigued. The book explores the long-distance running habits of the Tarahumara Indians of Mexico.

At first Hetherington used Vibram FiveFinger shoes, a minimalist footwear that fits the foot like a glove, and joined a barefoot running e-mail group. Then she plunged in all the way.

"I wanted to throw my arms in the air because it felt so glorious," she said of her first run, which consisted of running up and down her block.

Hetherington, who belongs to Lake Merritt Joggers and Striders, a local running group, said she can run on smooth concrete without shoes for 5 to 7 miles. Along the way, she's pulled a few muscles and gained a few splinters. The only blisters she's ever gotten, she said, are from shoes.

Rarely in pain

Overall, she said her Achilles' heel now rarely hurts and her form has significantly improved.

When barefoot, she tends to strike with the front and middle of her foot, she said. In contrast, with shoes on, she mostly hits the ground with the heel first, which she blames for contributing to her long-ago injuries.

"I do strongly believe this is one of the reasons people get running injuries - forces going through the body in the wrong way," she said.

The changes Hetherington describes have also been seen by Daniel Lieberman, a Harvard University professor of human evolutionary biology, who has been studying the mechanics of barefoot running for almost a decade.

The average-shoed runner lands on his or her heel. But in studies in the journal Nature, Lieberman and his team have showed that most experienced barefoot runners tend to hit the ground with their forefoot or mid-foot, generating a comparatively smaller, less jolting impact.

Therefore, the theory goes, runners don't need elevated, cushioned shoes to run on hard surfaces.

No good studies yet

But the jury is still out on whether running in bare feet actually results in fewer injuries, experts say. A big factor is running form, which varies from athlete to athlete and hasn't been controlled for in research so far.

"We're waiting for good studies to come up," said Dr. Anthony Luke, UCSF's director of primary care sports medicine and medical director of the San Francisco Marathon. "I hesitate to say as a rule (if) everyone should be running barefoot - because if you run with bad technique, but you have shoes or no shoes, you still have bad technique."

Anecdotal benefits

Bob Loomis of Concord said he knows barefoot running isn't definitively less harmful, but he has plenty of anecdotal evidence of its benefits.

During the 1982 San Francisco Marathon, which he ran in shoes, he attempted to overcorrect for a blister on his right foot and ended up bruising the bottom of his left foot. A nerve problem on the right side of his back also kicked in.

He stopped running, but missed it. He thought of the few times he'd enjoyed running barefoot at the park and on the beach. Inspired, he embarked on his first shoeless run in May 2011 and has kept it up since.

"I ran more and more barefoot," he said, "and I noticed I didn't have any of the recurrent pain problems I had before."

The 73-year-old retired newspaper editor has limits: He uses thin-soled shoes for rough surfaces and keeps runs under 5 miles.

Terry Orsi, 39, has gone one step further. The Stockton man has run an estimated 1,000 miles barefoot - including two 5K races, two 10Ks, four half-marathons and one 50K. He is also president of the Barefoot Runners Society's San Francisco Area chapter, which has more than 140 members.

Orsi swears he feels better and recovers faster after running barefoot than he did when he wore shoes, despite what studies have yet to show.

The only scientific finding that could persuade him to give up his hobby, he said, would be learning that "it will literally kill you.'"
