It’s springtime and flip-flops — the airy sandal with the distinctive thwack-thwack soundtrack — are back, much to the frustration of podiatrists (but to the delight of their billing departments). Wearing flip-flops can cause problems ranging from stubbed toes and cuts to overuse injuries such as foot stress fractures.
Now that the weather is warm, says Howard Osterman, a podiatrist who has practiced in Washington for 20 years, he will see at least one patient with a flip-flop injury every day through September.
Osterman treats a lot of tourists whose flip-flops aren’t up to rigors of eight-hour days tromping across the Mall — “kids from Wisconsin who didn’t know they’d need a podiatrist when they went on vacation,” he said.
But the “main culprits” doing themselves damage, he says, are young staffers and interns on Capitol Hill who pound the marble floors of Congress in flip-flops (hopefully on their way to change into more professional footwear) or ballet flats.
The No. 1 problem he sees from the shoes are overuse injuries such as stress fractures of the metatarsals, the five long bones that reach out to the toes. A stress fracture happens after constant, repetitive stress to a bone and is generally treated with rest, more-supportive shoes and perhaps a walking boot.
Many of the less-expensive flip-flop styles consist of just a flat piece of rubber and the toe thong. The lack of arch support can cause another common foot injury: plantar fasciitis, inflammation of the thick band of tissue along the bottom of the foot that causes a stabbing pain, especially in the heel. People with flatter arches are more prone to such overuse injuries because they need more support for their muscles and ligaments, Osterman says.
Flip-flops also leave the feet unprotected and exposed to the elements, which can mean cold toes, sunburns, cuts and bruises.
Very few studies have looked at the pros and cons of flip-flops. In 2008, Justin Shroyer, a biomechanics graduate student at Auburn University in Alabama, studied 39 college-age men and women to see how they walked when wearing flip-flops compared with sneakers. A native Floridian and a lifelong fan of flip-flops, Shroyer was inspired to study the shoes when he noticed how many fellow students wore them all day long and when he realized that it was a practically untouched area of research in biomechanics.
Shroyer, now an assistant professor at the University of Louisiana at Lafayette, found that while wearing flip-flops, participants in his study took shorter steps. He hypothesized that this was because the wearer was trying to get his or her foot on the ground faster, to prevent the shoe from flying off. Also, flip-flop wearers did not bring their toes up as much during the leg’s swing phase because they tended to grip the sandals with their toes.