"We became interested in flip-flops when we noticed an increase in lower leg pain when our students came back from summer and were transitioning back into wearing tennis shoes and street shoes," said Prof. Wendi Weimer of Auburn University, who set up an experiment with her graduate students to look at how the foot hits the ground. Participants were asked to wear either sneakers or thong flip-flops.
Auburn graduate student Justin Shroyer explained that their test showed that people are "very concerned about stubbing their toes particularly as they swing their leg through."
"What we found is that people take shorter strides and that their ankle angle ? the angle between their shin and the top of their foot ? is actually increased ? [We] attribute the change in ankle to protecting the toes as the foot swings through, but also to keeping the flip-flop on the foot so that it doesn't fly off as they swing forward. And so they do alter their gait," said Shrover.
With the average American taking between 10,000 and 20,000 steps each day, the small changes in one's gait can add up to serious injury.
"The major shock absorption occurs back on the heel, and if the surface between the heel and the ground is not supported it does not allow the heel to absorb shock as well as it should. Which means the foot works harder than it should and people tend to develop overuse injuries such as tendonitis, or in this case, lower leg, knee, hip and back problems," explained Dr. Rock Positano from the Hospital for Special Surgery in New York.
Fortunately for flip-flop fanatics, Positano says you don't have to throw away those thong sandals quite yet.
"Look, this is not an attack on a flip-flop or a flip-flop like shoe. Once again, it has to do with when you wear the flip-flop. If it's for hanging out around the swimming pool, or hanging out around the beach, or hanging out with your friends, they're fine," he said.
For the Beach:
For Longer Wear (with more support):
For A Little Extra Workout: