Unless you have a subscription to Nature, you can’t read the article that this picture accompanies, but it’s striking (pun!) nonetheless. A bit of explanation:

If you normally run with shoes, especially ones with big, padded heels (read: most shoes) then you’ll run with what’s called a “rear-foot strike” or a “heel strike” or a “heel-toe strike.” That is, you’ll land on your heel, roll through the mid-foot and push off with your toes.

This probably even feels natural. I know it does to me — when I wear shoes, at least.

The middle graph of impact forces shows how steep and irregular is the pressure of your body weight coming down on your feet when you’re wearing shoes and running like this.

The top graph shows the exact same thing, except the pressures are even steeper and more jagged. Or, in science-speak: “Both RFS gaits generate an impact transient, but shoes slow the transient’s rate of loading and lower its magnitude.” That’s what happens when you run barefoot and use the same technique as when you run with shoes.

But now take a look at the bottom graph. That shows a type of running called a “fore-foot strike” and it’s the type of running gait that most barefoot runners will accustom to naturally (pun!) and it’s the type of running that you’ll see if you go to a primary school playground, and watch kids who haven’t yet overcompensated  for their shoes.

That graph shows a smooth, natural weight transfer. I think that’s because instead of landing hard on a bony heel, you’re letting your ankle absorb some of the weight by flexing and then pushing off.

I’ve said this before, but I’m pretty sure now that I’m buying a pair of Vibram Fivefingers.

Original Nature article here, if you happen to have a subscription. The abstracts says:

Kinematic and kinetic analyses show that even on hard surfaces, barefoot runners who fore-foot strike generate smaller collision forces than shod rear-foot strikers. This difference results primarily from a more plantarflexed foot at landing and more ankle compliance during impact, decreasing the effective mass of the body that collides with the ground. Fore-foot- and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.

(via @nxthompson)