May 29, 2008 (Indianapolis) -- No one flaunts those killer heels like the gals of Sex and the City. But if this week's release of the movie has you yearning for some fab spikes of your own, you may want to opt for some fashionable flats instead.
A new study suggests that walking down stairs while wearing heels raises the chance of foot and ankle injuries. But don't go too far the other way: A second study shows that flip-flops may lead to lower-leg pain.
Both studies were presented at the annual meeting of the American College of Sports Medicine.
High Heels Lead to Unsteady Gait
High-heel researcher Lalitha Balasubramanian says several studies have shown that just walking down the street in heels can lead to everything from blisters and bunions to backaches and sprained ankles.
In what she believes is the first study of its kind, Balasubramanian and colleagues looked at the motion of the ankle joint in 11 college-aged women as they descended a flight of stairs. Balasubramanian is a graduate researcher in bioengineering at Louisiana Tech University in Ruston.
Normally, when walking down stairs, you put your heel down first and then flatten the foot. Then you use your toe to propel yourself forward.
But when wearing 2-and-1/2-inch heels, the women took on an unsteady gait, she says. "They'd land much more softly than is typical on their heel, and then the foot went flat. Then, they they'd put a lot of force on their toe in order to move the body forward to the next step," Balasubramanian says.
The researchers didn't study whether wearing high heels actually led to injuries. But Balasubramanian tells WebMD that an unsteady gait could lead to excessive muscle activity in the lower leg, which could precede a foot injury.
The study also showed that when barefoot, the women walked more confidently, placing more force on their heel.
The bottom line: "Limit your use of high heels, especially if you have foot injuries or back problems. And certainly limit the height of the heel," Balasubramanian says. Her suggestion: A 1-inch chunky heel at most.
Flip-Flops Linked to Abnormal Gait
As comfy as they may be, flip-flops may also lead to abnormal changes in your stride, other researchers say.
Justin F. Shroyer, a graduate student at Auburn University in Alabama, and colleagues studied 39 men and women aged 19 to 25.
Compared to when they were wearing sneakers, participants struck the ground with less force when donning flip-flops, he says.
This decreased force may explain anecdotal reports that people who wear flip-flops for extensive periods alter their normal gait and experience lower leg pain, Shroyer tells WebMD.
Shroyer says that because they lack the support that a walking or running shoe provides, flip-flops should only be worn for short periods of time, "like when you go to the beach. They should not be your primary form of footwear."
Also, replace flip-flops every three or four months, just as a runner would with running shoes, Shroyer says.
Jeffrey A. Ross, DPM, a clinical professor of medicine at Baylor College of Medicine in Houston, says forget the heels and the flip-flops: Invest in a good running shoe instead.
"Look at your shoes, and make sure they are not worn out. Over time, the soft cushiony material called EVA (ethylene vinyl acetate) breaks down and the shoe loses its resiliency. Good shoes with good shock absorption is a must," he tells WebMD.