High Heels, Barefeet, and Running in Circles
Three new studies recently emerged that shed light on how gait changes our structure and function. I thought it would be interesting to discuss them all at the same time.
High heels are bad
It is known that wearing high heels tends to shorten the calf muscles and stiffen the achilles tendon. Shocker. Some researchers were curious what effects this might have on gait mechanics. So they recruited a group of women who wore high heels (more than 5cm) for at least 40 hours a week for two years. The control group rarely wore heels.
The women walked barefoot while the scientists collected data. Analysis revealed that the high heel group on average took shorter strides and did more work with the calf muscles to propel themselves forward. The low heelers used longer strides, stretched their achilles tendons further, and thereby gained more forward energy "for free" in the form of the release of the stored energy of the elastic tendons. Score one for low heels.
Minimal footwear is good?
In another recent study, Daniel Lieberman's group recruited some people who habitually run with minimal footwear to run in their minimal footwear and then in normal running shoes. Guess what? Their gait was more efficient in the minimal footwear. This should be no major surprise. I would expect anyone to run most efficiently in the shoes they are accustomed to using. The study would have been more interesting if it included runners who wear mainstream running shoes. Would they have more or less efficient gaits than the minimal runners? Would they improve if they put on the Vibrams? We don't know. But the study does show that footwear affects gait efficiency.
Running in circles
In the third study, researchers recruited a bunch of runners who spend a lot of time running around a track in the same direction. They found that the muscle reflexes were different from side to side. This was not found in the control group, so this was interpreted as an adaptation to the monotonous same direction running.
So what is the take away here? For me, it is that the structure and function of the body are always adapting to imposed stress in highly specific ways. Some of the adaptations will probably be harmless, and others will probably lead to problems (e.g. the high heels). But one way or the other, how you move will leave its mark.