Most of us have been wearing high heels ever since we were old enough to clip-clop around in our mother’s shoes. Who hasn’t nursed a blister (or 100), as well as swollen and just plain sore feet, in order to wear a cute/gorgeous pair of heels? And you’ve probably said out loud a time or two, “What am I doing to my feet?”

A group of Australian researchers really wanted to know, so they recruited nine young women who had worn high heels for at least 40 hours a week for a minimum of two years for their study on what high heels are doing to women’s feet at the muscle and tendon level. The scientists also recruited 10 young women who rarely, if ever, wore heels to serve as the control group.

The heel-wearing women were asked to bring their favorite pair of high-heeled shoes to the lab. There, both groups of women were equipped with electrodes to track leg-muscle activity, as well as motion-capture reflective markers. Ultrasound probes measured the length of muscle fibers in their legs as they walked a 26-foot walkway several times.

In results published in The Journal of Applied Physiology, the scientists found that heel wearers moved with shorter, more forceful strides than the control group, their feet perpetually in a flexed, toes-pointed position. This movement pattern continued even when the women kicked off their heels and walked barefoot. As a result, the fibers in their calf muscles had shortened and they put much greater mechanical strain on their calf muscles than the control group did.

The researchers determined that high heels may ultimately increase the likelihood of strain injuries. They advised that if you wear heels and are concerned about muscle and joint strains, to wear high heels maybe “once or twice a week.” Or at the very least, remove the heels whenever possible, such as when you’re sitting at your desk.

Your feet will thank you!