We’ve all heard that heels can cause serious damage to our feet, backs, and bodies in general. As I recently strapped on one of my favorite pairs and saw a sexier, longer version of my legs in the mirror, I got to thinking about the power of heels. The confidence factor they give me is non-negotiable—regardless of the harm (and the anti-feminism of them) it’s pretty unlikely that I’ll ever quit wearing them. With that realization, I wondered what sorts of health issues I should be prepared for. Are there some heels that are less cruel to our bodies than others? A recommended regimen of how often we should wear flats? High heels, reportedly, were first used back in the Middle Ages to help people keep their feet in stirrups as they rode horses. And ever since Carrie met Mr. Big, we’ve all felt entitled to our own collection of glamorous, confidence-inducing spikes. And I’m hardly the only one unwilling to give up my claim to Carrie-like gams. “Probably nothing would convince me to stop wearing them,” says Amber Hearst. “An extreme injury might stop me for a little while,” says Maria Madeiros. “But I’d go back when I could.” It’s this extreme dedication that has foot and spine experts worried. Skeletally Speaking … Big, small, bony, pudgy, our feet endure tremendous pressure on a daily basis. An average day of walking, according to the American Podiatric Medical Association brings a force equal to several hundred tons down on our tootsies … and that’s in foot-friendly walking shoes. Yet we continue to squeeze them into our high-up, hard-to-balance heels (for good reason, of course). Podiatrists classify any shoe with a heel of more than two inches as dangerously high, “bio-mechanically and orthopedically unsound.” Yikes. High heels alter our body’s balance, forcing it to find a new equilibrium. Dr. Richard Brassard, the president of the American Chiropractic Association, compares the musculoskeletal system to a mobile, hanging in perfect harmony with each part balancing the other. When we alter one part (our feet), the whole system has to compensate. Wearing heels for any length of time does just that—it increases the normal forward curve of the back, causing the pelvis to tip forward. By bringing the heel up, we also shorten our hamstring muscles and change our center of gravity. The change in foot position alters the way we walk, moving the center of gravity to the ball of the foot. And the higher the heel, the more that center of gravity shifts and the more compensating our bodies have to do.