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The Barefoot Professor
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Material de apoyo al Seminario de Biomecánica impartido en el IES ALPAJÉS en 2015
I've been a runner all my life, and I've run with shoes pretty much all that time.
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But as a result of this research, I thought I should try barefoot running,
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and I actually have to say I've really enjoyed it. It's been a lot of fun.
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Humans have been running for at least 2 million years,
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and of course for most of that time, humans were running barefoot.
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And modern running shoes were actually only invented in the mid-1970s.
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So we have this idea now that in order to run, all you need are a pair of shoes.
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It's a common statement, right?
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Well, actually, that's not true.
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You don't need shoes.
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You just need feet.
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There's probably two stages in the evolution of the foot.
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Initially, the foot evolved for walking
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and also to climb trees.
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But at some point in human evolution,
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we think around two million years ago,
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there was a big environmental change in Africa,
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and the woodlands started disappearing
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and the savannas started growing.
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And at that point, new foods started appearing,
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and one of them, of course, was meat.
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There were all these ungulates out there on the grasslands.
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And in order to become a hunter, I think humans started to evolve running.
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And what we're good at is running at speeds that make animals gallop.
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And if you do that in the heat for a long period of time,
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that animal will overheat because quadrupeds cannot pant and gallop at the same time.
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So imagine you're chasing a gazelle or a kudu or some big animal.
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If you can chase that animal, make that animal gallop for 10 to 15 minutes, you've got dinner.
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We wanted to figure out how people ran without shoes
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before the shoe was invented
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because people have been running for millions of years
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and we weren't really sure what happens when barefoot runners run
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and how well they can do it.
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So we started bringing in habitual barefoot runners into the lab
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just to see how they use their bodies and how they use their feet.
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All right, here we go.
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Three, two, one.
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What we discovered was that barefoot runners run often very differently from the way your
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typical shod runner runs.
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So the shoe has got a big heel and it's designed to make it very comfortable to land on your
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heel and so a lot of shod runners land on the heel and then they bring the rest of their
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foot down.
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So when you land again on your heel, your body comes to a dead stop, there's a lot of
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mass and so there's an impact, there's a rapid force.
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It's like somebody hitting you on the heel with a hammer about two to three times your
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body weight.
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So when we started bringing barefoot runners into the lab, we discovered that they didn't
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like to do that, right?
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They typically landed on the front of their foot pretty horizontally, not like that, but
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just a little bit, so that they land underneath the heads of the fourth and fifth metatarsal
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often, and then they bring the heel down.
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And when we ran them over force plates, we discovered that they didn't have that big
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spike, that impact transient, that is typically associated with a heel strike.
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So what barefoot runners tend to do is by landing more towards the front of the foot
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and then letting the heel come down afterwards, and what that does is it converts the energy
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that would otherwise be a dead stop, right, the vertical deceleration of the leg, it converts
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that into rotational energy.
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You can understand the difference with the following very commonplace observation.
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Imagine dropping the pen onto the ground but falling vertically down, that's like your
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heel strike where your entire leg strikes the ground and comes to a stop and it's a
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big impact force.
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On the other hand, if you're a forefoot striker then you can think of it like the pen landing
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at an oblique angle where it hits the ground and it doesn't come to a dead stop but starts
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rotating.
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So not all the kinetic energy of the pen has to be absorbed by the impact, some of it gets
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is transferred from moving down to rotation and so the impact forces are much smaller
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in a forefoot strike compared to a heel strike.
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A lot of runners get injured and what they get typically often are repetitive stress
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injuries.
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And so one hypothesis is that that impact caused by landing on the heel, which causes
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that big impact transient, could be injurious and it's associated with pain in the soft
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tissues at the bottom of the foot, it's associated with shin splints, may cause some other kinds
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of injury.
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So our hypothesis is that individuals who don't land on their heel, but avoid those
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big impacts by landing on the front of their foot, may be less susceptible to those kinds
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of repetitive stress injuries.
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So we've been studying barefoot runners now for quite a while, and we went to Africa,
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we looked at people who've never worn shoes, and they've been running 20 kilometers a day,
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and I just decided I had to try running barefoot myself.
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So I, last summer actually, I was running one day and I just decided to take my shoes
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off and I found it was just incredibly fun and since then I've actually started running
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barefoot frequently and I have to say I really love it.
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It feels great.
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I've stopped heel striking and I now have become a forefoot striker and it's fun.
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- Idioma/s:
- Autor/es:
- YOUTUBE
- Subido por:
- Francisco J. M.
- Licencia:
- Reconocimiento - No comercial - Compartir igual
- Visualizaciones:
- 74
- Fecha:
- 6 de enero de 2015 - 0:09
- Visibilidad:
- Público
- Centro:
- IES ALPAJÉS
- Duración:
- 06′ 16″
- Relación de aspecto:
- 1.78:1
- Resolución:
- 640x360 píxeles
- Tamaño:
- 20.47 MBytes
