Flips-flops are bad for your sole

Flip-flops aren't just hazardous to politicians — they also pose risks for your feet. The floppy footwear, once contained to the beach, can now be spotted year-round.

That's a problem, say foot specialists.

Most flip-flops offer no arch support and cause people to alter their gait because of the extra work it takes to keep them on.

Podiatrists say they see more complaints of plantar fasciitis (heel pain and inflammation) during the summer months, particularly after people get back from vacation.

"I definitely see issues with people when summer comes and all they're in is little flimsy flip-flops," said Dr. Seth Anderson of Missouri Foot and Ankle in Creve Coeur, Mo.

Flip-flops were originally intended for short distances, namely to protect feet from the hot sandy beach. Now they're worn to work, weddings and even the White House.

Flip-flops launched a footwear fiasco in 2005 when several members of the Northwestern women's national champion lacrosse team wore them to a visit at the White House. Etiquette gurus cringed at the exposed toes shown in photos of the offending soles.

But aside from any dress code or etiquette violations, flip-flops aren't so bad for anyone with perfect feet. "Usually if you don't have underlying issues and you're somewhat sensible about it you can get away with wearing sandals more often," Anderson said.

Better than barefoot

Flip-flops can even be protective by preventing people from stepping directly on glass or rocks and by keeping feet free of plantar warts and athlete's foot infections that can be contracted in public areas.

"It's actually an advantage from going barefoot," said Dr. Michael Weiss, a St. Louis podiatrist.

But anyone with flat feet, high arches, bunions, hammertoes or other foot issues can be at risk for exacerbating their problems by wearing flip-flops.

Flip-flops should also be avoided by anyone with diabetes or circulation problems because symptoms can include a lack of sensation in the feet. Any cuts or abrasions might not be noticed and can lead to infections.

Podiatrists say that people with knee, hip or back problems need to wear more supportive shoes so they don't aggravate their injuries.

Pain from flip-flop wear can extend from the feet up into the ankles, legs, hips and lower back, say researchers at Auburn University in Alabama.

In a study of the mechanics of flip-flops, the researchers had 39 people walk on a platform wearing flip-flops or athletic shoes and then measured the force when their feet hit the ground. A video camera was used to measure the length of the study participants' strides and the angles of their legs. Their findings were presented at last year's meeting of the American College of Sports Medicine.

When wearing flip-flops, the stride is shorter and the foot rolls inward because of the lack of support. The front of the foot doesn't come up as high when the leg swings forward and the heel hits the ground with less force. Toes curl up to grip the shoe and keep it from slipping off.

All of that can cause overpronation, where the foot rolls inward too far and doesn't absorb enough shock, leading to pain and tendinitis.

$20 billion industry

The continuing popularity of flip-flops means many people are unaware or unconcerned about any health risks. Sales figures for the ubiquitous flip-flops are hard to come by. But the Atlanta-based company Flip Flop Shops claims the shoes spawned a $20 billion industry that topped the sales of sneakers for the first time in 2006. If accurate, those figures are remarkable since it only takes a dollar at some bargain shops to slap on a pair of flip-flops.

In general, the cheaper the flip-flops, the worse they'll be for your feet.

The American Podiatric Medical Association (http://www.apma.org/) recommends bending a flip-flop to see how supportive it is. The shoe should bend at the ball of the foot, never in the middle. Make sure the material is made of soft leather that won't cause blisters.

The association approves of certain brands of flip-flops, including Chaco, Sole, FitFlop, Vasyli and Wolky.

Birkenstocks and Crocs are also better choices for people who can't stand to wear socks and shoes in the summer. The sandals, while arguably less flattering, offer better support than the flat thongs.

To further enhance the safety of flip-flops, only wear them for short periods and replace them every three to four months.