Katie Fogarty falls down at Prada spring 2009 runway show

Walking around in high heels all day never really feels good, but you get used to it, right? Not so fast. A new study published in the International Journal of Clinical Practice found that even though wearing heels might seem easier with time, they’re actually wreaking havoc on your body.

Researchers from Hanseo University in South Korea recruited 40 healthy female college students for their study. The women were studying air tourism and service, and were required to wear high heels to class. The researchers grouped them by class and studied how their bodies reacted to four years of high heels.

The Armadillo shoes from Alexander McQueen spring 2010 show measures at an otherworldly 12 inches tall!

Though wearing heels at first strengthened ankle muscles, it ended up weakening them and causing an imbalance by senior year, which is a key predictor of future injuries. Women who wore shoes with 10-centimeter (3.9-inch) heels more than three times a week ended up developing an imbalance in four ankle muscles.

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If you wear heels, the study’s authors recommend you regularly perform exercises that strengthen your ankles. Walk around on your heels, try “toe tappers” to stretch your muscles, and stand up and down on your tiptoes to strengthen your calves. And if you can get away with wearing sneakers or flats once in a while, that’s even better.