Eleonora Carisi and Valentina Siragusa. during Milan Men's Fashion Week Spring/Summer 2016 on June 20, 2015 in Milan, Italy. Valentina wears Italia Independent sunglasses, a Diane von Furstenberg dress, and Fendi bag.
Credit: Melodie Jeng/Getty Images

When it comes to summer sandals, the styles run the gamut. We have espadrille wedges, slides, lace-up heels, gladiator flats, block-heels, flip-flops, delicate ankle-strap sandals, and countless more. As major advocates of happy feet, we wanted to know which style was the worst of the worst for your poor soles, alignment and whatnot. We already found out the healthiest heel height, but what's the unhealthiest sandal style to step into?

We turned to foot expert Dr. Emily Splichal, podiatrist and human movement specialist, who gave us the lowdown.

"Flip-flops that have just the one-thong strap are the worst," she resolutely says. "Because flip-flops are not attached to the foot, your toes grip onto them when you move, which changes the way you walk."

To what kind of sandals should we be shopping for?

"Sandals that lock around the ankle, so it's attached to the foot," Splichal says. "They will keep the way you walk closer to normal."