The Human Foot Is a Design Disaster - Cheddar Explores

The Human Foot Is a Design Disaster - Cheddar Explores

%Our feet were originally meant for climbing and grasping but four million years ago and possibly earlier some Apes started dabbling in bipedalism.%

Experts haven't agreed on why hominins developed this trait, but it probably had something to do with being more efficient while scavenging or tracking prey over long distances.

Bipedal locomotion is a notoriously difficult task, and our feet have evolved to cope with it. Our toes became shorter, stiffer, and more in line with each other, and our ligaments got thicker to help hold all of our bones in place.

this guy made history in 2012 for being

the first amputee runner to compete in

the Olympic Games its Oscar Pistorius

who you might also know for murdering

his girlfriend but this is a video about

feet so let's set that aside Pistorius

had to fight for his right to compete in

the Olympics by proving to officials

that his blade-like prosthetic feet

didn't give him an extra advantage over

athletes running on regular old flesh

feet there are other blade runners

fighting the same fight behind him the

German long jumper Marcos rim was barred

from competing in the Rio Olympics the

college track athlete hunter Woodhall

had to make the case to the NCAA and

Paralympian Blake Leeper is gearing up

for the same fight to compete in the

2020 Olympics and it all makes you

wonder why does the foot designed in a

lab look so different from the

biological human foot it might be

because the human foot is kind of a

design disaster podiatry is a five

billion dollar industry a majority of

Americans will experience significant

foot pain at some point in their lives

and as many as 10 percent of us will

experience inflammation in the band of

tissue along our arches otherwise known

as plantar fasciitis why though weren't

humans evolved to walk long distances

and isn't walking upright on two legs

the trait that first separated us from

other primates so why hasn't natural

selection selected a cooler better less

injury-prone foot for us some theories

posit that we're so plagued by foot

problems because we evolved to walk

barefoot out of nature over soft sweet

earth but now we've thrown off the

delicate biomechanical balance of our

feet by wearing big mushy cushiony

tennis shoes meanwhile our bones take a

beating from walking and standing on

super hard surfaces like concrete but

other researchers say it goes back way

further than that jeremy de silva is an

anthropologist who studies human

evolution and argues that foot problems

exist way back in the fossil record

fossils show evidence of osteoarthritis

and compression fractures and flat

arches which means foot pain millions of

years ago

DeSilva makes a convincing case that the

real source of our foot problems is the

janky design as I mentioned earlier what

we're looking at are our paper clips and

duct tape our primate ancestors spent

most of their time in trees our feet

then were originally meant for climbing

and grasping but four million years ago

and possibly earlier some Apes started

dabbling in bipedalism experts haven't

agreed on why hominins developed this

trait perhaps it was a more efficient

way to travel while scavenging for food

or maybe it was to enable persistence

hunting tracking prey over such long

distances that they became overheated

and simply laid down from exhaustion

no weapons required whatever the reason

bipedalism is the defining trait of

humans going bipedal involved some

painful and atomic ultradox including

everything from where the spine attaches

to the skull to the angle of the femurs

and of course the shape of our feet

let's talk mechanics a foot is a

propulsive lever it needs to be stiff

enough that we can push off the ground

and propel ourselves forward but it

needs to be elastic enough to store the

mechanical energy that's generated each

time the foot strikes the ground

that's how designers ended up with this

blade shaped for athletes the human foot

on the other hand has 26 bones 33 joints

and over a hundred muscles tendons and

ligaments that's because it was built

for grasping all those joints let it

flex so it's not inherently rigid enough

to give us the propulsive power we need

here's what had to change back when we

were climbers our big toe used to be

opposable like our thumbs but to help

make the foot more rigid it became

shorter stiffer and in line with our

other toes and we developed arches to

absorb the force of impact each time our

foot hits the ground

our ligaments got thicker to help hold

all these small bones firmly in place

bipedal locomotion is a notoriously

complex mechanical engineering puzzle

that scientists have been working on for

decades

and in the case of human feet you could

say natural selection is still in the

early design phase DeSilva uses the

ostrich as an example of a foot from the

natural world that resembles the

prosthetic blades that were perfectly

designed for running on two feet but he

also points out birds have a big

bipedalism head start just look at their

ancestors

they've been bipedal for 230 million

years while we've only been bipedal for

about five million and a big take away

from his talk natural selection isn't

selecting from an endless menu of

options rather it's a constant series of

small modifications to the original

design so in our case it slowly modified

flexible grasping hands into more rigid

propulsive levers which left us kind of

vulnerable to some aches and pains but

considering our feet are modified a pans

they do a pretty good job and

considering where the most successful

primate neh mammal neh species on the

planet it's a pretty decent compromise

thanks for watching if you're super

interested in the scars of human

evolution you can see the whole talk on

Boston University's YouTube page if you

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thanks again we'll see you next time