COLUMBIA — Rock Bridge High School* student Erin Greer wears flip-flops every day.
“If it’s not cold, I’m wearing flip-flops,” said Greer, who has three pairs for everyday casual wear. She said she replaces them only when they are severely worn.
“I wear them until they’re falling apart,” she said.
Flip-flops may be the most popular footwear on the planet. They have been in and out of American fashion since the 1950s, with a widespread revival in the 1990s for both men and women.
The same shoes are called thongs in Australia, chappals in India and zori in Japan. In developing countries, they are typically the cheapest footwear available, often made from recycled tires and sold for the equivalent of $1.
Yet for years, doctors have warned that wearing flip-flops for long distances could be painful. Podiatrists don’t recommend wearing them for daily use because they can cause pain in the feet, knees or even lower back.
“What I usually recommend in regards to flip-flops, is to use them when you’re not going to be on your feet much,” local podiatrist Scott Foster said. “They are not an everyday shoe.”
He said pain in the feet, knees or lower back usually comes from the lack of support. Wearing flip flops can also expose too much air to feet, which can have a negative effect.
“It causes feet to dry out, especially around the heels,” Foster said.
The pain can go away by wearing different shoes, but dry feet could take months to heal, he said.
Studies have even shown that wearers walk differently.
In June 2007, doctoral student Justin Shroyer compared walking in flip-flops to walking in athletic shoes at Auburn University in Auburn, Ala. His research showed that people take shorter strides when wearing flip-flops.
“We had people wear both flip-flops and tennis shoes and we measured the kinematics of each shoe,” he said. This involved measuring stride length and ankle angle.
“When you wear flip-flops you take shorter stride lengths," Shroyer said. "There is an increased ankle angle. You don’t bring your toes up as much.”
Doctors' warnings and research results don't seem to have made a dent in flip-flop fashion.
According to flip-flop manufacturer Peche blu the shoes have grown into an industry estimated at $2 billion.
On the social network site Facebook, 1.1 million people are fans of the shoes on two flip-flop sites. On Friday, these were a typical posts on one site: "The most ingeniously devised 'shoes' ever!" (Beth Fierro of Las Cruces, N.M.); "The only thing better than flips is bare feet" (Denise Graff of Minneapolis).
Earlier this month, Gap reported that clothing sales were down 6 percent for May, except in Old Navy stores. According to the New York Times, the increased sales for Old Navy was stimulated by a $1 sale on flip-flops.
The Dessy Group, a wedding supplier in New York, offers flip-flops for bridesmaids in 50 colors. Tracy Asai Designs, an online source of shoes for weddings, offers bridal flip-flops in white or ivory moire taffeta for $50.
In July 2005, the lacrosse team of Northwestern University was photographed wearing flip-flops on a visit to the White House. News reports called it "the flip-flop flap," citing a front-page headline in the Chicago Tribune that read: "You wore flip-flops to the White House?!"
Dan Quinn, manager of American Shoes in Columbia said flip-flops are here to stay. “It’s not a trend, it’s a lifestyle at this point,” he said. “There was a time that about 65 percent of shoes sold were tennis shoes, but those days are gone.”
He estimates that 20 percent of his inventory is flip-flops.
Justin Shroyer found in his study that differences in walking can be attributed to trying to keep the flip-flop on your foot. He noted that people “scrunch their toes” to keep them on.
He intends to continue his research on flip-flops, hoping to compare flip-flop features such as flat bottoms, arch supports and heels. He also said people compare wearing flip-flops to going barefoot, and some say that this is better for human foot development. Shroyer wants to look into that, too.
Lindsay Wilson, a recent graduate of Mexico High School, said she wears flip-flops five days a week in the summer and did notice a change in her walking.
“I curl my toes to keep them on,” Wilson said. “I walk slower.”