ABC TV in Australia has a very good segment on science called Catalyst. They recently did a segment comparing barefoot and shod running, and did an excellent job showing the science and highlighting the differences.
Here’s the main thing to get out of it, from Professor Joseph Hamill:
The prime thing is in my research is that barefoot running forces you to change the things that you normally do.
The show then went on to show three different measurements from running: joint movement, stress on the body, and muscle activity.
First, a picture of the subject (the reporter) with all the sensors strapped to his left leg.
For the joint movement, little reflective balls were attached above and below his joints. In this picture, the white stick contains the reflective ball, while the red device is used to calibrate where the joint is relative to the balls.
Of course, one of the major changes that happens when you run barefooted is that you can no longer heel strike, at least not without really feeling it. So most folks switch to a mid- or fore-foot landing. Here’s a shot from the joint movement demonstration of landing with shoes on.
And you can compare that to the landing when barefoot.
That really shows the difference, doesn’t it?
Moving on to the landing stresses, this picture says it all.
It was also in Lieberman’s paper, but you can see the effect of the heel strike at the cursor. That is quite an impact. The other curve shows the much more gradual increase from barefoot running. No wonder people’s knees hurt when they run shod.
Finally, here’s a chart they generated on muscle activity, comparing the calf muscle (in the back) and the front leg muscle. Barefoot running is in red.
As you can see, when shod, it is the front leg muscle that is getting the workout (right-hand graph), while when barefoot running, that shifts to the calf muscle. This is exactly the effect that barefoot runners notice.
One of the main thing the professors get out of this is that the transition time from shod running to barefoot running really should be taken slowly and carefully:
What we’ve shown is that transition time is probably you’re at the greatest risk of being injured. What happens to people who transition from shoes to barefoot running they change to the foot fall pattern. And in fact when you ran you changed. And foot fall patterns like a heel/toe pattern, those are very, very, very deeply engrained in your motor program. It’s hard to change that.
And so when you’re forced to change that I think that there’s a greater possibility for certain types of injuries.
I think that also says why toe-shoes aren’t a very good idea: if your soles are protected it is way too easy to succumb to over-exuberance.
The story itself is here, with a full transcript.
And here’s the full video. Make sure to check it out yourself.