[ExI] The natural human gait (Re: Barefoot running)

[J. Stanton]

On 1/16/12 4:00 AM, spike wrote:
> Tom, this misses something important.  In order for toe running to be
> practical even for short distances requires a particular build that is
> common in Kenyan runners (the subject of the New Scientist article) but very
> rare in Americans.

Spike, you're way off base here.  There is no "build" necessary to run 
with the natural human gait: as Lieberman's group points out, 
heel-striking is unnatural and causes greater impact no matter how much 
weight you carry.  What certain West African runners (e.g. the Kalenjin) 
have is long legs and relatively skinny calves, meaning they are moving 
less weight when they run.  This gives them an efficiency advantage at 
distance running.  (Sprinting is more dependent on peak power, so 
sprinters tend to have muscular builds.)

Lieberman's laboratory and research can be found here:
http://barefootrunning.fas.harvard.edu/

Also, the natural human gait does not involve running purely on the 
toes.  You land on the outside of the ball of your foot and roll towards 
your heel, which impacts the ground as your lead foot passes behind your 
body.  Thus, the arch of your foot compresses and absorbs the shock of 
impact -- which is why we have arches in the first place!  Then you push 
off with your big toe, which is pointed forward on toe-off.

Note that "pronation" is therefore part of the natural human gait, and 
not a defect to be avoided!  Pronation is only bad when you're forced 
into an unnatural heel-striking gait by your shoes.  "Arch support" is 
also an artifact of heel-striking: since the arch has no function in 
this unnatural gait, its muscular support atrophies, often requiring 
"arch support" to hold it up so that it doesn't collapse inward and 
screw up your ankle alignment ("pronation").

In support of toe-striking, anyone who has tried to run cross-country 
(not "trail running" -- running across open ground that is neither a 
lawn nor a trail, as we did for the millions of years which shaped us 
into modern humans) will find that a heel-striking gait will quickly 
cause you to turn your ankle.  In order to run safely on irregular 
ground, you must land toe-first, which allows your heel to descend in a 
controlled manner -- or fail to descend, if your proprioception detects 
a hole there.  In contrast, the usual combination of heel-striking and 
overstriding leads to an uncontrolled toe slap as the much weaker shin 
muscles are unable to stop the descent of the toes.

Note that it is necessary to start slowly and with short distances (< 
1/2 mile) with barefoot/minimal running.  The muscles of your foot will 
be atrophied from years of wearing a cast ("running shoes"), and it will 
take time to strengthen them.  Also it will take a while for you to 
develop a natural gait that doesn't overstride but lets your hips rotate.

I know more than one person who has cured decade-plus foot issues (pain, 
inability to run or walk distances) by switching to minimal shoes.  Feel 
free to ask me questions on the subject, including "what shoes should I 
look at?"

JS
http://www.gnolls.org