The Science of High Heels: How Physics Keeps Women From Falling Down

How on Earth do women walk in high heels? Seriously now . . . shouldn't they tip over?

The answer is: Science.

Lady Gaga's massive 10-inch tapered heels may be purely for show, rarely making an appearance outside of the artist's music videos. But three-inch or higher heels are hard for many people to understand -- even scientists.

"Many of my physicist colleagues have no trouble understanding quantum mechanics but can't figure out how women can wear high heels," admitted Dr. Laura Grant, a physicist from Liverpool University.

Yet the recipe for safe stilettos seems fairly straightforward: Two parts sacrifice and a dash of solid steel, said Fred Allard, creative director for Nine West, one of the world's largest manufacturers of women's shoes.

"In the center of the mold, a steel rod is inserted for safety and solidity purposes," Allard told FoxNews.com. "The density of the plastic in the heel is also very important, and we make sure during production that no air bubbles get into the center, which can cause weakness."

Got it? A tiny piece of leather is suspended by steel and plastic (hopefully more steel than plastic). But how do women walk in them? Or Prince, for that matter?

Turns out, there's a formula for that. In 2004, researchers at the University of Surrey devised an equation that uses shoe size, the Pythagorean theorem, and several sociological variables to calculate how high heels can safely go: h = Q x(12+3s /8)

Variables in the equation include aesthetic appeal of the shoe, experience in wearing high heels, how many months the shoe has been in style, and even the amount of alcohol consumed.

Really.

The cost of the shoe plays a factor too, said Dr. Paul Stevenson of the University of Surrey, who developed the equation.

"Clearly, if the shoe is particularly expensive, you can put up with a higher heel," Stevenson said.

Obviously, it's not exact science. But it does give would-be wearers an idea of how much height they can tolerate. In most cases, five inches seems to be the max, though Allard said Nine West puts no limit on the height of a heel. "The height is only limited by the foot's configuration within the shoe," he told FoxNews.com.

But wearing high heels requires more than balance. They demand sacrifice: Sacrifice in comfort. Sacrifice in practicality. Sacrifice in stability. Sacrifice in mobility. And in some cases, sacrifice in health, including knee, hip, feet, and back injury, as documented by WebMD.

In other words, beauty is pain. Women don't wear heels because they are comfortable; they endure the pain because the tradeoff is looking really hot.

Why all the health risks? Science can explain that too. Specifically, Newton's third law of motion, which states for every action there is always an equal and opposite reaction.

In laymen's terms, the weight of a woman's body is almost entirely focused on a heel the size of a pencil eraser, which creates immense pressure for such a small area. Much more, in fact, than a 6,000-pound elephant -- which explains why elephants can walk on grass but women in spike heels can't without sinking into the ground.

Conversely, that immense pressure reflects back into the shoe wearer's heel, back, and everything in between, which explains the associated health risks to the body. That said, heels can also have a positive effect on well-being.

"They have a way of making me feel better about myself," Dani Gooch, a high-heeled mother of two told FoxNews.com. "In that sense, I feel more confident in them than I do in other shoes."

Exactly, said shoe designer Terry DeHavilland.

"People say they're bad for the feet, but they're good for the mind. What's more important?"

Blake Snow is a freelance writer amazed by how women wear high heels. He lives in Utah with his wife and children. Suggestion box and contact information can be found on his website.