Auburn University researchers have found that wearing thong-style flip-flops can result in sore feet, ankles and legs. The research team, led by biomechanics doctoral student Justin Shroyer, presented its findings at the recent annual meeting of the American College of Sports Medicine in Indianapolis.
"We found that when people walk in flip-flops, they alter their gait, which can result in problems and pain from the foot up into the hips and lower back," Shroyer said. "Variations like this at the foot can result in changes up the kinetic chain, which in this case can extend upward in the wearer's body."
The researchers, in the AU College of Education's Department of Kinesiology, recruited 39 college-age men and women for the study. Participants, wearing thong-style flip-flops and then traditional athletic shoes, walked a platform that measured vertical force as the walkers' feet hit the ground. In addition, a video camcorder measured stride length and limb angles.
| Auburn University biomechanics doctoral student Justin Shroyer places reflective markers on the foot of Ph.D. student Joanna Booker. Shroyer led an AU research team in a study of the effects of flip-flops versus those of athletics shoes.
Shroyer, who owns two pairs of flip-flops himself, said the research does not suggest that people should never wear flip-flops, but should wear them in moderation. Flip-flops can be worn to help beach-goers avoid sandy shoes or to give athletes a post-game alternative to filthy cleats, but are not designed to properly support the foot and ankle during all-day wear, and, like athletics shoes, should be replaced every three to four months.
"Flip-flops are a mainstay for students here on campus but they're just not designed for that kind of use," he said.
The study included thong-style flip-flops from well-known retailers and manufacturers and ranged in price from $5 to $50. Athletic shoes included in the study also ranged in price and style.Shroyer's interest in flip-flops has other footwear applications, as well as applications in other areas of biomechanics research. He will apply conclusions from the flip-flop study to his dissertation research on specialty athletics shoes and how they support the foot and aid in biomechanic performance.