The Science of Barefoot Running

The biggest problem is that anyone who feels the need to express an option either way, tends to be firmly in one camp or another.  They will be evangelical about their chosen side and fiercly closed minded to the other view.  It worked for them, so it must be the same for everyone else. Whatever you think you believe, you should always keep an open mind, or you may miss out on new information.  After all, you want to be right don’t you?  Science is constantly being proved wrong by newer science.  This is the very nature of real science – the quest for truth.  You should never forget this.

Below is a simplified version of the science for barefooting so far.  I’ll make references to the research where necessary, but this is really designed as an overview and a starting point for your own reading on the subject.  Nothing can substitute for reading the original research yourself and making up your own mind.

Barefoot Running

Given the forty years of running shoe development, and all the ‘technology’ built into each new running shoe.  You would have thought that the science journals would be full of studies done over the years on how modern running shoes have improved our experience and reduced injury rates.  Yet in all the time the modern cushioned running shoe has been around, there have been no such studies and injury rates remain the same.

Only now are we starting to see studies into barefoot running and comparisons with shod running.  However these studies are still thin on the ground, mainly because there is no money to be made in trying to disprove the validity of cushioned running shoes. Several recent studies have looked at the two different running styles that tend to go hand in hand with shod vs barefoot running.  The Heel Strike (shoes) vs the Forefoot Strike (barefoot or barefoot shoes). Using pressure pads, they measured these foot strike types on runners and revealed that the difference in impacts were dramatic. Whilst both strike types peak at the same load of between 2 and 3 times body weight, how they get there is very different.

Heal Strike

Sharp juddering impact increases by 2x body weight in 250 milliseconds – concentrated purely on the heel.  Notice the sharp spike at the start?  This near vertical pressure loading curve does not appear naturally.

Source: Harvard University

Forefoot Strike

Uniform bell curve that takes 600 milliseconds to load the same 2x body weight shift in pressure as above.  This is more than double the time your body has to adjust to the load compared with the Heel Strike above.  Plus this load is being distributed out over your whole foot – a bigger surface area.  More of your foot as more weight comes down. Strike is the wrong word for a forefoot landing really, as the foot doesn’t strike down at all.  It’s more akin to a perfectly executed plane landing.  When the pilot has got the angle just right and there’s not even a bump.  The only difference being that unlike the plane, your foot has matched the relative speed of the ground exactly and touches down without any linear friction  That’s how an experienced barefoot running touches down.  Forefoot Touchdown (FT) rather than a Forefoot Strike (FS) is the right way to think about it.

Source: Harvard University

The theory is that this impact transient is one of the major reasons for running injuries.  The body isn’t built for this sudden change in impact force.  The heavy cushioning in running shoes makes it possible to run like this and not feel the unnaturally high impact due to the removal of proprioceptive feedback through the foot and heel.