At the NY Times Blog, A scientific look at the dangers of high heels tells us what every woman who shows off her legs knows but doesn’t want to hear…
“Whether high heels might likewise affect the wearer’s biomechanics and injury risk has received scant scientific attention, however, even though millions of women wear heels almost every day. So, in one of the first studies of its kind, the Australian scientists recruited nine young women who had worn high heels for at least 40 hours a week for a minimum of two years. The scientists also recruited 10 young women who rarely, if ever, wore heels to serve as controls. The women were in their late teens, 20s or early 30s.
It was obvious, as the scientists had suspected watching the woman during their coffee break, that the women habituated to high heels walked differently from those who usually wore flats, even when the heel wearers went barefoot. But the nature and extent of the differences were surprising. In resultspublished last week 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.
In that control group, the women who rarely wore heels, walking primarily involved stretching and stressing their tendons, especially the Achilles tendon. But in the heel wearers, the walking mostly engaged their muscles.
That biomechanical distinction is important, says Dr. Cronin, who is now a researcher at the University of Jyvaskyla in Finland. “Several studies have shown that optimal muscle-tendon efficiency” while walking “occurs when the muscle stays approximately the same length while the tendon lengthens. When the tendon lengthens, it stores elastic energy and later returns it when the foot pushes off the ground. Tendons are more effective springs than muscles,” he continues. So by stretching and straining their already shortened calf muscles, the heel wearers walk less efficiently with or without heels, he says, requiring more energy to cover the same amount of ground as people in flats and probably causing muscle fatigue.
But the risk of injury is not. “We think that the large muscle strains that occur when walking in heels may ultimately increase the likelihood of strain injuries,” he says. (This risk is separate from the chances that a woman, if unfamiliar with heels, may topple sideways and twist an ankle or bruise her self-image, which is an acute injury and happened to me only the one time.)
The risks extend to workouts, when heel wearers abruptly switch to sneakers or other flat shoes. “In a person who wears heels most of her working week,” Dr. Cronin says, the foot and leg positioning in heels “becomes the new default position for the joints and the structures within. Any change to this default setting,” he says, like pulling on Keds or Crocs, constitutes “a novel environment, which could increase injury risk.””
Not all the research in the world will stop women wearing heels, so what are we to do? This is the scientist’s advice:
“So, if you do wear heels and are at all concerned about muscle and joint strains, his advice is simple. Try, if possible, to ease back a bit on the towering footwear, he says. Wear high heels maybe “once or twice a week,” he says. And if that’s not practical or desirable, “try to remove the heels whenever possible, such as when you’re sitting at your desk.” The shoes can remain alluring, even nestled beside your feet.”
Credit: Illustration by Henrik Sorensen