The Naked Foot: Thoughts for the Shoe Minimalist
/Authors: Dr. Shawn Allen, Dr. Ivo Waerlop, Coach Chris Korfist
This may be one of the very first articles we ever wrote for The Gait Guys. It must be 7-8 years old now, before the barefoot-minimalist craze ever started. It is a bit dated, but we think that it was time to revisit its contents. You will see that many of our early core principles have not changed and you can see the thought process of where the fads and trends were projected to go. Wind your mind back a near decade, and read on !
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If you want to follow the fad craze these days, just look to companies like Vibram and Nike. Vibram is the company that has brought you the soles and treads of many of the shoes you have worn over the years and of course Nike are the people who first brought you the “running shoe” as we know it today. Nike first brought us the waffle bottom trainer, the cross trainer, air pockets, “shocks” and, the Air Jordan and now their barefoot minimalist series, the Nike Free. Now, we are sure not many of you have heard of the “Vibram Five Fingers” barefoot slip-on ‘shoe’ but virtually everyone who runs in some manner has seen and heard about the Nike Free. What initially stymied us when they first came out was the obvious question of “Why would the same people who sell us the shoes, and give us so many varieties and categories to choose from, now be advocating that we train barefoot, or close to it? ” Or are they ?
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(Addendum: this article was originally written long ago, at the start of this fad, the fad that has become a trend. The article traveled fast around the internet and garnered us much attention including a gig with Vibram as consultants. But that was then, this is now. We, and the trend have come a long way, and so has the research. Some supportive for the trend, some disagreements and plenty of controversy. The remainder of this article has been unedited, hence its tense and outdated verbiage, shoe types and research. But we thought it was time to review before moving ahead.)
The Nike version they are pushing, first the Nike Free 5 and now down to the Nike Free 3, has a light weight thin flexible sole and thin vamp top cover material whoís purpose is to merely hold the shoe onto the foot. The Vibram device, which is a fascinating yet simple slipper, is even more simplistic but has some brilliance built right into its heart. It is merely a rubber sock with compartments for each individual toe but that is part of its brilliance. So why would Nike and now Vibram go against their own creations and advocate that we begin walking and running barefoot, or at least become more “shoe-minimalists” after decades of building shoe and sole lines that previously were designed for various conditions, foot types and activities ? There appears to be sound moral reasoning if you delve into the research, but you have to look closely and you have to be careful you do not have one of those foot types that could lead to problems with this type of footwear (but that is a topic for another article to come soon, see Part II).
Barefoot theories are nothing new. In 1960 Abebe Bikila, perhaps the greatest barefoot runner of all time, won the first of his consecutive gold medals without shoes setting a world record of 2:15:17. Englandís Bruce Tulloh was setting overseas records into the 1960’s running unshod, skin to the ground. Today Ken Bob Saxton is one of the most visible barefoot marathoners, long beard and all, and is an advocate of the technique.
With the introduction of the Nike Free, the interest in barefoot running resurfaced at the turn of the century. An article by Michael Warburton, published as an internet paper on barefoot theories, seemed to spark some of the resurgence of the method of running. In his brilliant paper he had some interesting thoughts and pointed out some noteworthy facts. He indicated that research showed that an extra mass of 100 grams attached to the foot diminished the economy of running by one percent. Thus, two 10 ounce shoes (the weight of a lightweight training shoe) could compoundingly cripple you by more than five percent in efficiency. In tangible terms that could be more than six minutes tacked onto a world class marathoner, taking a world record time to a mere first group finishing time. So, it is a question of weight and time, or is there something more ?
To get started with some hard and simple research facts, current research has been conducted showing that plantar (bottom of the foot) sensory feedback plays a central role in safe and effective locomotion, that more shoe cushioning can lead to higher impact forces on the joints and higher risk of injury, that unshod (without shoes) lowers contact time versus shod running, that there are higher braking and pushing impulses in shod versus unshod running, that unshod running presents a reduction of impact peak force that would reduce the high mechanical stress that occurs during repetitive running and that the unshod foot induces a neural-mechanical adaptation which could enhance the storage and restitution of elastic energy at ankle extensor level. These are only some of the research findings but they are some of the more significant ones. These issues will not only support injury management benefits for the unshod runner but increase speed, force and power output.
Stepping backwards in time a little, in the caveman days things were different. The foot was unshod (without shoes) from the moment of the first step until one’s dying day, and thus the foot developed and looked different. The sole of the foot was thicker and callused due to the constant contact with rough and offending surfaces thus preventing skin penetration, the foot proper was more muscular and it may have been wider in the forefoot and the toes were likely slightly separated due to the demands of gripping which would obviously necessitate increase muscular strength and bulk to the foot intrinsic muscles. It was the constant input of uneven and offending surfaces such as rocks, twigs, mud, foliage and debris that stimulated the bottom of the foot, and thus the intrinsic muscles, sensing joint positions and relaying those variations to the brain for corresponding descending motor changes and adaptations to maintain protection and balance. The foot simply worked different, it worked better, it worked more like the engineering marvel that it truly is. The foot was uncovered and the surfaces we walked on were uneven and challenging. However, as time went on, man decided to mess with a good thing. He took a foot that was highly sensitive, a virtual sensory organ with a significant sensory and motor representation in the brain (only the hands and face have more brain representation as represented by the sensory and motor homunculus of the brain) and he not only covered it up with a slab of leather or rubber but he then flattened and then paved not only his world, but also his home, with black hard top, cement, wood or tile thus completing the total sensory information deprivation of the entire foot. Thus, not only did he take away critical adaptive skills from himself and generations to follow, but he began the deprivation of the brain of critical information from which the central nervous system would need to develop and continue to function effectively. It is not unlikely that the man of pre-shod time had a strong competent foot arch (perhaps somewhat flat to increase surface area contact for adaptation), but one that did not need orthotics, stability shoes or rigid shanks and inserts. In other words, the foot and its lower limb muscles were strong with exceptional skills and endurance. But in today’s day and time things are now different. We now affix a shoe to the child’s foot even before he can walk and then when he does, all propriosensory information necessary for the development of critical spinal and central nervous system reflexes is ensured to be virtually absent. Is it any wonder why there are so many people in chronic pain from postural disorders related to central core weakness and inhibition ? Is it any wonder why so many people seem to have flat incompetent feet and arches? Man has done it to himself, but thankfully man has proven that what he can do, he can undo. Thankfully we see modern medical research that has delved into this realm of thought and has uncovered the woes of our ways and to follow, companies like those mentioned earlier are imagining and developing devices that will allow us some protection from modern day offenses such as glass, plastics and metal and thus allow us the slow and gradual return to our healthier foot days, all fashion sense aside.
Shawn and Ivo, The Gait Guys
Two fellas that were here at the beginning, and two fellas that will be here for the duration.
