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Tuesday, February 09, 2010

Running barefoot is better, researchers find

Scientific American: January 29, 2010 By Katherine Harmon

Mother Nature has outpaced science once again: the bare human foot is better for running than one cushioned by sneakers. What about those $125 high-tech running shoes with 648 custom combinations? Toss ‘em, according to a new study published online January 27 in the journal Nature

“Most people today think barefoot running is dangerous and hurts,” Daniel Lieberman, a professor of human evolutionary biology at Harvard University, said in a prepared statement. “But actually you can run barefoot on the world’s hardest surfaces without the slightest discomfort and pain … It might be less injurious than the way some people run in shoes.”

Lieberman and his group used 3-D infrared tracking to record and study the running and strike style of three groups of runners: people who had always run barefoot, people who had always run with shoes, and people who had switched from shoe to shoeless.

They found that when runners lace up their shmancy sneakers and take off, about 75 to 80 percent land heel-first. Barefoot runners—as Homo sapiens had evolved to be—usually land toward the middle or front of the food. “People who don’t wear shoes when they run have an astonishingly different strike,” Lieberman said.


Comparing the footfall of two Kenyan runners from the study: The runner on the left has worn shoes most of his life and lands on his heel, whereas the runner on the right has primarily run barefoot and lands on the ball of her foot.

Without shoes, landing on the heel is painful and can translate into a collision force some 1.5 to 3 times body weight. “Barefoot runners point their toes more at landing”, which helps to lessen the impact by “decreasing the effective mass of the foot that comes to a sudden stop when you land,” Madhusudhan Venkadesan, an applied mathematics and human evolutionary biology postdoctoral researcher at Harvard who also worked on the study, said in a prepared statement. But as cushioned kicks have hit the streets and treadmills, that initial pain has disappeared, and runners have changed their stride, leading to a way of high-impact running that human physiology wasn’t evolved for—one that the researchers posit can lead to a host of foot and leg injuries.
Gary comments:
Barefoot running is fast becoming the in thing. While I am a fan of going barefoot I have serious reservations about the message in this article.

There is enormous benefit for children going barefoot for most of the time until at least puberty. My sister, Lorraine, attributes some of her marathon running success to her having very strong feet from a barefoot childhood in rural New Zealand. The same for me! But I am not about to urge all my readers to go and run their next marathon barefoot.

Despite the Professorial input, this study displays an ignorance of basic biomechanics and lack of understanding of the practical challenges of running on modern surfaces.

The average Kenyan male runner is very thin and wiry and probably less than 50kg weight. Allometric scaling (Read about it here) means that a 50kg runner can run barefoot with much less risk of injury than an 80kg runner. Allometry tells us that a 30kg child running on pavement only needs leather slippers when running; whereas an 80kg runner is best served wearing shoes with substantial shock absorption.

Kenyan runners typically have enormously strong feet hardened by physically robust childhoods and being mostly barefoot - very different to the feet of the Western raised person.

The foot is designed for negotiating rough natural terrain that constantly changes in texture. The monotonous environs of hard concrete pavement throw enormous and unrelenting stresses on the foot that it simply was never designed for.

There is a big difference between running a few Km in a lab setting and training daily on a paved road.

There are two types of running: Ball of the foot first. Toey runners tend to be very good up to about 3-5 km races; but much further and they tend to be excessively injury prone. Running landing on the ball of the foot is the most natural way to negotiate rough terrain. It is also the natural way to sprint; but not to run a marathon on hard pavement. Artificial surfaces that have no give demand artificial solutions to reduce the sudden shock wave of foot impact - Shoes. And heel first landing.

Why heel first is best
When the forefoot hits the ground first, the impact shock is absorbed over a small area of the foot within a brief space of time. It is that sharp shock wave that causes the damage such as stress fracture and shin splints. Nature has the answer - heel strike!

Please refer to the graphic of the foot while reading what follows.
When the heel hits the ground two shock absorbing mechanisms simultaneously kick into gear (There are other mechanisms but we will not complicate matters any more than they need to be).

The sole of the foot is a quarter moon shape. This is an ingenious mechanism to spread the shock wave over time and over a distance longer than the length of the foot. The heel strikes the ground then the sole of the foot prescribes a circular motion, rolling smoothly forward over the ground to finally push off at the pad of the big toe. The orange arrow shows how this happens and explains why a healthy foot causes wear on the outer portion of the heel of the shoe.

The other action happening is the arch of the foot is compressed like the leaf springs of a car suspension as depicted by the lilac arrows. This action absorbs shock wave energy which is stored in the elastic tissues. This stored energy is released as the foot pushes off the ball of the foot and the big toe. Ingenious!

When a runner lands forefoot first, the leaf spring kicks into gear, but the shock-spreading heel roll is absent. Great for sprinting but not for running a marathon on pavement, even with shoes.

While forefoot running may be best for short, fast sprints or a lithe Kenyan loping across the African Savannah, it is a sure recipe for injury for the larger and less "barefoot conditioned" city raised athlete.



This video shows that heel landing causes much greater shock than ball - midfoot landing

Gary Moller said...

Thanks for the link Rick. I have seen this before and have now embedded it into the article.

I'll wait and see the response from readers and then do an update. I believe I am right and they are wrong - to the extent I have explained in the article.

While I type this I am barefoot but I am not about to go and run on the pavement without shoes. Barefoot on the beach is okay for me. How about you?.

Incidentally, the shoes I race and train in are light racing flats - I weigh just over 60kg.


I agree, I would not wish to run on a man made surface barefoot, but heel striking is not natural, only shoes with a high heel will allow it.
Run in a light flexible shoe ball-heel, if you land heel first you are missing out on the foots natural shock absorber, the arch!!! which not only takes in the energy of foot strike but gives you return of energy like a trampoline :]

Gary Moller said...

The arch works during heel strike.

The great factor being overlooked in this whole debate is allometry.

I'll do an update to further explain my position.

Wayne said...

heavy runners ned decent shock absorbing, i doubt racing flats will work for them if they are running a reasonable mileage.even at 75 kilos I"ve found teh amount and quality of shock absorbing matters, not to hard , not too soft
racing flats also ten to have a thin outer sole and a general lighter construction all round and dont last as long.

Wayne said...

i think theres some psycological phenomenon about buying sports gear,
Sir bob jones said the secret to becoming wealthy was charging people a lot of money and htey would think they are getting a good service.
people are convinced in advance that by forking over the big bikies they are getting something better. when they may be getting overkill.
perhaps it also encourages them to use it and value it because they have forked out all that money.
teh shoes youi want when you are a slow runner are probably different than the shoes you want when you are a fast runner,
throwing money at a problem is not necessarily the best answer,
there are plenty of other sports that will take all teh money you have, I thought hiking coats were expensive till I saw a sailing coat that was three and a half times the price of my expensive hiking jacket!
dont be too quick to pursuade yourself you can buy yourself into something better.
arthur lydiard said, "there are no shortcuts" running shoes won't put the hard effort in or make you much faster.
an triathlete in NZ turned up to a top national triathlon with a steel racing bike twice the weight of the high tech alloy and carbon bikes and came third!

Gary Moller said...

If you look at some of the photos of my sister Lorraine you will see that her marathon shoes are very light basic shoes. Her racing weight was under 60kg.

I have the same size feet so have several pairs of her shoes that I still jog in. Some are as old as 30 years and still usable.

If a runner is light and runs efficiently, then sole wear on the shoes is minimal as is wear on the legs.

Anonymous said...

Hi Gary. The writers of that report said that it would be widely mis-reported by the world's media with exactly the 'throw out your shoes' reaction that we are seeing. The actual title of the report is: Foot strike patterns and collision forces in HABITUALLY barefoot versus shod runners. Dan Lieberman who wrote the report said ""controlled prospective studies are needed to test the hypothesis that individuals who do not predominantly RFS either barefoot or in minimal footwear, as the foot apparently evolved to do, have reduced injury rates" Basically the report confirms what has been known for years, that barefoot runners show lower impact forces. The report is available here:
Kind regards

Gary Moller said...

That I can agree with! As per my earlier comment, my barefoot childhood explains why I seldom wear out a pair of running shoes. It also explains why Lorraine's shoes were always in such good condition whenever she gave me her old shoes.

I think shoes should be as close to moccasins as one can comfortably do, bearing in mind the terrain and the principles of allometric scaling.

Gazelle run very differently to the way of the elephant.

Thanks for the clarification Paul.

Unknown said...

Why do we have to always (and only) consider how the foot has evolved to perform? Why not also consider how the body has acclimatised/adapted to the stressors that it has been exposed to during an individual's lifetime? Example - a distance runner who has weak hip abductors is typically prone to over pronation. If the foot isn't accustomed to this, the runner may experience grief in the archilles, tibialis posterior, medial aspect of the tibia, plantar fascia, etc. My notion is that most good running shoes will either lessen the degree of over pronation and/or reduce the impact placed on the medial aspect of the foot/lower limb. No shoes = opposite = excessive tension in tib. post. + plantar fascia and much much more.

My view - barefoot running can be ideal, but only if the individual is suited for it (biomechanically). Sure; we all may have evolved to run barefoot. But, because of some "modern occupations", some people may not be suited for it due to changes that have occured in the balance that the body holds between different muscle groups.

Interesting article. Love it.


Anonymous said...

My personal experience (70kg ultradistance runner)
Since changing from heel strike to midfoot strike ('pose technique') 3 years ago I got rid of multiple Achilles and ITB ailments and run today (49 years old) just as fast as 5 years ago. Also, midfoot striking makes 'freewheeling' downhill much faster with less strain on the knees and quads. I run in Nike Free or racing flats.
Just my 5 cents worth...

Wayne said...

only those people of lean build are still adapted to run long distance, the human body has eveolved to form different body shapes, some are big and muscular and broad, they are too heavy to comfortably run very far at all, everytime they make footfall their larger bulk takes more energy to lift them off the ground and more damage is created when they hit the ground, they have evolved for feats of physical strength, such as shifting weights, rather than shifting their own weight over the ground. its wrong to think you can get a shoe to help everyone run free from injury, the heavier your build the bigger the problems you will have even before you confider issues such as pronation and supination and imbalances.
some people shouldnt try and habitually run long distances, they can't tolerate the mileages of the lean runners.

Unknown said...

The discussion is about the techniques of running.
But let's not forget about the running surfaces. Parks and public areas these days are mown by big gang mowers which chop garbage like aluminium cans into small shards of shrapnel, and bury them amongst the clippings.
Meanwhile louts and vagrants hurl bottles onto synthetic tracks and pavements and even the best cleaning leaves the smaller splinters to be imbedded in bare feet...
Its simply not safe to run in bare feet, whatever the science says!