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 !

_____________________

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 ?

  • (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  The remainder of this article has been unedited, hence its tense and outdated verbiage, shoe types and research.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. 

Podcast #29: DARPA Robots & Cartilage in Runners

podcast link: 

http://thegaitguys.libsyn.com/podcast-29-darpa-robots-cartilage-in-runners

iTunes link:

https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

Gait Guys online /download store:

http://store.payloadz.com/results/results.aspx?m=80204

other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen  Biomechanics

Today’s show notes:

1. Neuroscience Piece:
Human or Robot? Harder to Tell In Latest Bipedal Robot PETMAN Video
http://singularityhub.com/2013/04/07/human-or-robot-harder-to-tell-in-latest-bipedal-robot-petman-video/

Boston Dynamics is building the bipedal PETMAN (Protection Ensemble Test Mannequin) for the Defense Advanced Research Projects Agency (DARPA).

_____________
2.BIOWARE
How do we fit into this growing paradigm (bioware) and the bionics paradigm

_______
3.  http://www.sciencedaily.com/releases/2013/04/130408184727.htm

Human or Robot? Harder to Tell In Latest Bipedal Robot PETMAN Video

In their study published in the American Journal of Physiology: Regulatory, Integrative and Comparative Physiology on April 3, 2013, Roberts and Booth put rats in cages with running wheels and measured how much each rat willingly ran on their wheels during a six-day period. They then bred the top 26 runners with each other and bred the 26 rats that ran the least with each other. They repeated this process through 10 generations and found that the line of running rats chose to run 10 times more than the line of “lazy” rats.

4. Defending Barefoot

http://drnicksrunningblog.com/2013/04/04/experts-defend-barefoot-running-shoes-despite-new-evidence-indicating-the-footwear-could-promote-bone-injury/

5. hunter7979 asked you:

 Hey I have been injured for a long time I was hoping you could give me some insight on how to treat it. Started with ITBS in both knees about two years ago. Somehow my pelvis got thrown out of whack and I ended up with funky gait and scoliosis. I feel like my left leg is shorter, internally rotated and pronating. Supposedly my right leg is actually a tiny bit longer but not enough to make a real difference. Orthotics helped balance out my pelvis but I still walk/run funky. Appreciate it guys

6. Disclaimer

7.  How does your sport change your gait?
Twitter post we did….The Gait Guys (@TheGaitGuys)
4/4/13 1:18 PM
Doing lots of “in the guard” strategizing in jiujitsu last few weeks. Hip flexors are getting punished & inhibiting Glutes and hip extension.
8. Epidemic of Crocs footwear in the fort Meyers airport! No wonder we have so many gait problems. Would like to get @TheGaitGuys opinion!


A Scientific Look at Heeled Shoes. A nice follow up to the Zero Drop trend this week.

This blog post was from a year ago, but seems to be appropriate to follow up our two “zero drop” articles this week. Enjoy

http://well.blogs.nytimes.com/2012/01/25/scientists-look-at-the-dangers-of-high-heels/

Can you think of a better way to start the week than with a discussion of high heels? We all like high heels… Well, at least guys do (and we know quite a few women who do as well…some of you may be reading this post). NO, WE DO NOT LIKE TO WEAR THEM, but we can admire the way they make the calves look so great and the increased lumbar lordosis and accentuation of the greatest gait muscles ever created!

Were they based off “chopines” from the 15th century; an elevated shoe (7-30 inches high!) which kept the peoples feet literally “out of the muck” (they didn’t have modern plumbing back then) or are they older? Or was the heel invented out of necessity to keep horse riders literally “in the saddle” ? Chinese and Turkish history says maybe they were to keep women (particularly concubines) from escaping. For the intents of discussion, we will stick with this last premise, as it fits nicely with the findings of this article (based on the study published here)

Remember the neuromechanics posts on muscle spindles or golgi tendon organs (GTO’s) ? If not, click the links and check them out; suffice it to say that the take home message is: Spindles respond to length and GTO’s respond to tension.

We also remember that GTO;’s modulate the muscles function that they come from. In other words, they literally “turn off” the muscle they come from (it is a disynaptic, post synaptic pathway for you neuro geeks out there). In light of that, lets look at some quotes form the article:

“the scientists found that heel wearers moved with shorter, more forceful strides than the control group, their feet perpetually in a flexed, toes-pointed position. This movement pattern continued even when the women kicked off their heels and walked barefoot. “

No surprises here. Go up on your toes and take a few strides (more difficult for guys, since the biggest heel we may have is about 12mm in our running shoes). Which muscles are engaging? See how difficult it is to take a full stride? Try to engage your glutes. Not so easy, eh? Now put your foot flat on the floor, extend your toes and NOW engage your glutes. Easier? Presyanptic loading of the motor neuron pool pays big dividends!

They go on to say: “As a result, the fibers in their calf muscles had shortened and they put much greater mechanical strain on their calf muscles than the control group did.”

Hmmm… shortened muscles put under greater tension. Sounds like a job for the golgi’s, and what do they do? Inhibit the muscle from contracting. No wonder is was harder.

“In the control group, the women who rarely wore heels, walking primarily involved stretching and stressing their tendons, especially the Achilles tendon. But in the heel wearers, the walking mostly engaged their muscles.”

Wow, here is evidence They changed their motor programming!  Did you ever think that high heels could change the way our brain works? Maybe it’s a secret plot to take over the world….or maybe not…

The Gait Guys…Lovers of high heels as long as you don’t walk in them….

A Scientific Look at Heeled Shoes. A nice follow up to the Zero Drop trend this week.

This blog post was from a year ago, but seems to be appropriate to follow up our two “zero drop” articles this week. Enjoy

http://well.blogs.nytimes.com/2012/01/25/scientists-look-at-the-dangers-of-high-heels/

Can you think of a better way to start the week than with a discussion of high heels? We all like high heels… Well, at least guys do (and we know quite a few women who do as well…some of you may be reading this post). NO, WE DO NOT LIKE TO WEAR THEM, but we can admire the way they make the calves look so great and the increased lumbar lordosis and accentuation of the greatest gait muscles ever created!

Were they based off “chopines” from the 15th century; an elevated shoe (7-30 inches high!) which kept the peoples feet literally “out of the muck” (they didn’t have modern plumbing back then) or are they older? Or was the heel invented out of necessity to keep horse riders literally “in the saddle” ? Chinese and Turkish history says maybe they were to keep women (particularly concubines) from escaping. For the intents of discussion, we will stick with this last premise, as it fits nicely with the findings of this article (based on the study published here)

Remember the neuromechanics posts on muscle spindles or golgi tendon organs (GTO’s) ? If not, click the links and check them out; suffice it to say that the take home message is: Spindles respond to length and GTO’s respond to tension.

We also remember that GTO;’s modulate the muscles function that they come from. In other words, they literally “turn off” the muscle they come from (it is a disynaptic, post synaptic pathway for you neuro geeks out there). In light of that, lets look at some quotes form the article:

“the scientists found that heel wearers moved with shorter, more forceful strides than the control group, their feet perpetually in a flexed, toes-pointed position. This movement pattern continued even when the women kicked off their heels and walked barefoot. “

No surprises here. Go up on your toes and take a few strides (more difficult for guys, since the biggest heel we may have is about 12mm in our running shoes). Which muscles are engaging? See how difficult it is to take a full stride? Try to engage your glutes. Not so easy, eh? Now put your foot flat on the floor, extend your toes and NOW engage your glutes. Easier? Presyanptic loading of the motor neuron pool pays big dividends!

They go on to say: “As a result, the fibers in their calf muscles had shortened and they put much greater mechanical strain on their calf muscles than the control group did.”

Hmmm… shortened muscles put under greater tension. Sounds like a job for the golgi’s, and what do they do? Inhibit the muscle from contracting. No wonder is was harder.

“In the control group, the women who rarely wore heels, walking primarily involved stretching and stressing their tendons, especially the Achilles tendon. But in the heel wearers, the walking mostly engaged their muscles.”

Wow, here is evidence They changed their motor programming!  Did you ever think that high heels could change the way our brain works? Maybe it’s a secret plot to take over the world….or maybe not…

The Gait Guys…Lovers of high heels as long as you don’t walk in them….

Zero Drop? Think before you drop. More to think about before you make the jump (or run, or walk or stand…)

Ramp Delta. Drop. Heel to toe differential. Stack height differential. You have likely heard all the words before. We are talking about the difference in height between the center of the heel and ball of the big toe on the foot. It is literally “how much heel” the shoe has. Some have upwards of 20mm, some none at all (zero drop). The average seems to be 10-15 mm for many shoes, but that tradition is evolving to less and less (Brooks for example now has the “Pure” Series with a 4 mm average and one shoe that can be either 4 or zero (The Drift)). New Balance has their miniumus, Altra has their army of shoes, Saucony has a variable selection. Everyone is on target with their collection of minimalist or minimalist-trending (or as we like to call them, “gateway”) shoes.

Since we are born “sans” shoes, zero seems “natural” or maybe the best, right? Maybe, maybe not. A lot depends on you and your anatomy however logic dictates that we were born with the rear and forefoot on the same plane so there has to be a natural logic to the zero drop trend. The problem remains, how long have you been forcing this non-natural state and how long (if at all) will you be able to return to the “less is more” trend?

If you have been in shoes with more drop your whole life, your musculoskeletal system and neurology has adapted to that. If we take away our favorite chair, pair of shoes, golf club or whatever, you may have something to say about it. Same for your feet. If you drop/lower your heel, there are biomechanical changes and possible consequences.

You may have read this weeks post, talking about having enough ankle range of motion available. Dropping the heel requires more dorsiflexion (or extension) of the ankle. If that range of motion is not available, then the motion needs to occur somewhere else.

So, where elsewhere in the body is the motion going to occur ? Dropping the ankle requires more knee extension. Do you have that range of motion available? Are your knees painful when you wear a zero drop shoe?

How about your hips? Dropping the heel requires more hip extension as well. This extension is often accompanied by internal rotation of the hip (ankle dorsiflexion, along with foot abduction and forefoot eversion are all components of pronation, which will cause medial rotation of the hip. Do you have this range of motion available, or do you have femoral retro torsion, and a zero drop shoe makes that worse?

What about the effect on the low back? Dropping the heel decreases the lumbar lordosis (the natural curve forward). Don’t believe us ? Just look at any woman in a 3 inch pump and you will see some lovely curves. This places additional stress on the posterior ligaments and joint capsules and compression and shear on the discs. Some spines won’t tolerate this, just like some won’t tolerate heels, which increases the lumbar lordosis and places more stress on the posterior joints.

What about the mid back? Dropping the heel decreases the thoracic curve. How much extension (backward movement) do you have in your mid back?

The same with the neck…and the list goes on….

As you can see, it is much more complex than just changing to a shoe with less drop. Because of the biomechanical changes and demands, it will probably cost you something, be it range of motion, comfort, function. We are not saying it isn’t worth it, or that you shouldn’t do it; we are saying go slow and listen to your body. What may be right for someone else may not be right for you … . either in the short or long term.

Earn your way. Don’t throw caution to the wind. We see people everyday that have suffered the above consequences due to listening to the wonderful marketing of the minimalist trend and from embracing some of the nonsense on the web.  We call these people, “patients”.  Don’t make yourself a patient, use your head when it comes to your feet.

The Gait Guys

Ivo and Shawn

All material copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved. Please ask before lifting our material.

Zero Drop? Think before you drop. More to think about before you make the jump (or run, or walk or stand…)

Ramp Delta. Drop. Heel to toe differential. Stack height differential. You have likely heard all the words before. We are talking about the difference in height between the center of the heel and ball of the big toe on the foot. It is literally “how much heel” the shoe has. Some have upwards of 20mm, some none at all (zero drop). The average seems to be 10-15 mm for many shoes, but that tradition is evolving to less and less (Brooks for example now has the “Pure” Series with a 4 mm average and one shoe that can be either 4 or zero (The Drift)). New Balance has their miniumus, Altra has their army of shoes, Saucony has a variable selection. Everyone is on target with their collection of minimalist or minimalist-trending (or as we like to call them, “gateway”) shoes.

Since we are born “sans” shoes, zero seems “natural” or maybe the best, right? Maybe, maybe not. A lot depends on you and your anatomy however logic dictates that we were born with the rear and forefoot on the same plane so there has to be a natural logic to the zero drop trend. The problem remains, how long have you been forcing this non-natural state and how long (if at all) will you be able to return to the “less is more” trend?

If you have been in shoes with more drop your whole life, your musculoskeletal system and neurology has adapted to that. If we take away our favorite chair, pair of shoes, golf club or whatever, you may have something to say about it. Same for your feet. If you drop/lower your heel, there are biomechanical changes and possible consequences.

You may have read this weeks post, talking about having enough ankle range of motion available. Dropping the heel requires more dorsiflexion (or extension) of the ankle. If that range of motion is not available, then the motion needs to occur somewhere else.

So, where elsewhere in the body is the motion going to occur ? Dropping the ankle requires more knee extension. Do you have that range of motion available? Are your knees painful when you wear a zero drop shoe?

How about your hips? Dropping the heel requires more hip extension as well. This extension is often accompanied by internal rotation of the hip (ankle dorsiflexion, along with foot abduction and forefoot eversion are all components of pronation, which will cause medial rotation of the hip. Do you have this range of motion available, or do you have femoral retro torsion, and a zero drop shoe makes that worse?

What about the effect on the low back? Dropping the heel decreases the lumbar lordosis (the natural curve forward). Don’t believe us ? Just look at any woman in a 3 inch pump and you will see some lovely curves. This places additional stress on the posterior ligaments and joint capsules and compression and shear on the discs. Some spines won’t tolerate this, just like some won’t tolerate heels, which increases the lumbar lordosis and places more stress on the posterior joints.

What about the mid back? Dropping the heel decreases the thoracic curve. How much extension (backward movement) do you have in your mid back?

The same with the neck…and the list goes on….

As you can see, it is much more complex than just changing to a shoe with less drop. Because of the biomechanical changes and demands, it will probably cost you something, be it range of motion, comfort, function. We are not saying it isn’t worth it, or that you shouldn’t do it; we are saying go slow and listen to your body. What may be right for someone else may not be right for you … . either in the short or long term.

Earn your way. Don’t throw caution to the wind. We see people everyday that have suffered the above consequences due to listening to the wonderful marketing of the minimalist trend and from embracing some of the nonsense on the web.  We call these people, “patients”.  Don’t make yourself a patient, use your head when it comes to your feet.

The Gait Guys

Ivo and Shawn

All material copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved. Please ask before lifting our material.

Podcast #28: Nanotech, Athletes & Barefoot ?

podcast link: 

http://thegaitguys.libsyn.com/podcast-28-nanotechnology-athletes-minimalism

iTunes link:

https://itunes.apple.com/us/podcast/the-gait-guys-podcast/id559864138

Gait Guys online /download store:

http://store.payloadz.com/results/results.aspx?m=80204

other web based Gait Guys lectures:

www.onlinece.com   type in Dr. Waerlop or Dr. Allen  Biomechanics

Today’s show notes:

1. Neuroscience Pieces:

Technology is advancing so quickly that it won’t be long before the era of performance-enhancing drugs seems like the athletic Stone Age. Injecting or ingesting chemicals will be considered primitive when athletes will have the ability to have robotic cells powered by software coursing through their veins.

Russian Billionaire Wants to Create Cyborgs for Real

http://mashable.com/2013/04/01/avatar-project/


2.
Barefoot Running Can Cause Injuries, Too

By GRETCHEN REYNOLDS

http://well.blogs.nytimes.com/2013/03/06/barefoot-running-can-cause-injuries-too/
http://www.ncbi.nlm.nih.gov/pubmed/23439417

3. Running with sesamoiditis: How I resolved a 10 year injury by ditching my traditional running shoes. | Dr. Nick’s Running Blog
http://drnicksrunningblog.com/2013/04/04/running-with-sesamoiditis-how-i-resolved-a-10-year-injury-by-ditching-my-traditional-running-shoes/

4. Case
I have a question about peroneus longus in relation to “morton’s toe”. I did a very deep deep massage for an extended length of time and found that when I put my foot on the floor afterwards, the first metatarsal head was no longer raised!! Can you advise what may cause the peroneus longus to become tight, and if there any good stretches for it?
Thank you,Tracy

5. Do orthopedic shoes really help?
http://www.ncbi.nlm.nih.gov/pubmed/23496924

Well, they do seem to assist in foot placement and can enhance proprioception, so in the right circumstances, they can be an excellent adjunct to exercise and rehabilitation.

“Footwear adaptation led to pain relief and to improved foot & ankle proprioception. It is likely that that enhancement allows patients to better control foot placement. As a result, higher dynamic stability has been observed. LDS seems therefore a valuable index that could be used in early evaluation of footwear outcome in clinical settings.”

6. Shoes and Performance. Does it surprise you that it affects adolescents too? It shouldn’t:

http://www.sciencedaily.com/releases/2013/03/130319091420.htm