Monday, September 13, 2010
Why do running shoes have high heels?
So many running shoes look like high heels to me. I've always thought that, but still I've worn a few pairs over the years. I assume what caused manufacturer's to build up the heels in shoes designed for running was the erroneous idea that we do or should run heel-to-toe.
I find this idea strange. I assume the earliest humans, and even some of the later ones, had to run regularly during their lives to hunt, fight, flee, seek help, etc... but even so, the heel is clearly a poor design for striking the ground first when running. It's great to have another point of contact the ground when you want to stand or balance on one leg--witness the number of animals who sit up on their haunches with that backward pointing bend in their hind leg (analogous to our heel) resting on the ground). Of course, humans have other adaptations at the knees, hips, shoulders, and even the skull that other animals don't have and which make a two-legged stance efficient. We're adapted to stand on two feet, walk on two feet, but those flimsy, injury-prone heels aren't meant to take the kind of hard pounding they take when we make them the first point of contact while running. So, why do so many people do just that?
Well, research and observations of barefoot runners in many cultures around the world indicates that we probably heel strike because our cushy, high-heeled running shoes make it possible for us to do it without breaking our heels. Unfortunately, changing our form to a heel strike appears to have led to a variety of other problems in form that may contribute to the injuries that plague shod runners in Developed countries where shoes are ubiquitous. Meanwhile, in cultures where many people go barefoot by choice or necessity, researchers note that runners seem naturally to absorb the impact of foot strike by allowing the forefoot (ball of the foot) to strike the ground first with each step, and many don't even bear weight on their heel when running at all.
Indeed, even where high-heeled, cushioned sole running shoes and heel striking have become the norm, when we remove the shoes to run, we learn quickly to avoid heel striking. Unfortunately, we have grown up with high-heeled running shoes, and that has taken a toll on many of the musculoskeletal structure of the foot, weakening it by offering too much support and not allowing it to experience the mechanical stresses that provide the stimulus required to stimulate our bodies to built, reinforce, and strengthen our bones, ligaments, tendons, and muscles.
Ironically, our highly supportive shoes, designed to prevent injuries and correct supposed abnormalities in our gait biomechanics, have probably weakened us and possibly made injuries even more likely.
The jury is still out on much of this, but the evidence is beginning to point in this direction. Still, it doesn't mean you should throw your shoes away. Recall that if you have been a habitual shoe wearer, you are likely not ready to go cold turkey. You could hurt yourself with your weak bones and and connective tissues.
My approach, and it has worked well when I have not allowed myself to overdo it in training, is to gradually transition to shoes that offer less support. I may never decide to go without shoes altogether, because I enjoy the protection from sharp rocks and other hazards, but I've moved as far as cross country flats now, and I find that while my first run in them caused me some soreness afterward, now I run in them almost every time, I run with a forefoot strike, I run faster, I run more comfortably, and my calves and ankles and feet now feel stronger. So far, so good.