barefoot science

THE ZEPPA TIPPING POINT PROBLEM

A recent post on The Foot Collective FaceBook page titled Humans aren’t meant to walk on ramps!, highlighted the problems caused by elevating the heel above the forefoot known in the footwear industry as drop. Like the author of the post, I also wear zero drop shoes like Xero and Lems exclusively  (with NABOSO insoles) and spend all of my time indoors barefoot. Like the author, I too have experienced an immediate, unnatural and a sense of disorientation in terms of a connection with the ground, when I have worn dress shoes and winter boots with moderate drop.

While some amount of boot board ramp angle or zeppa appears to necessary for a strong, tensioned stance (what I refer to as a planted or rooted stance), the amount of zeppa is turning to be much less than I originally thought. It may be less than 1.5 degrees total (zeppa + delta). Assuming zero delta, there appears to be a very narrow range within which zeppa is optimal after which a tipping point is reached in terms of adverse effects on the motor control and balance systems.

It has also become apparent that some racers are tuning ski response by adjusting binding delta. Zeppa and delta each have a different effect on ski response especially edge control and the ability of a skier to resist the forces acting on them in the load phase of a turn. I will discuss issue this in a future post.


Humans aren’t meant to walk on ramps!

Powerful post by TFC Educator @optimize.physiotherapy
👣
Why do most shoes have a heel on them?
This really hit home the other day when I put on my winter boots (because it snows in November in Canada). Being someone who goes barefoot all day at work and at home (and wears zero drop shoes), it was a very unnatural feeling. It really threw my walking off, and I noticed the effects immediately. It changed the way I walked, stood, and made me use different muscles.
Humans are meant to have a flat base. No other animal wears mini ramps on their feet, but we do. The problem is that your body adapts to having a heel on, and it works different from a biomechanical perspective in any given movement pattern (the higher the heel, the worse the effect…but even most casual, running, and gym shoes have heels)


One thing it really does is affect your ankle/foot function. It has a huge effect on ankle ROM and tissue tension around the ankle. The problem is, when you wear a heel all day at work/at the gym/walking around, your tissues adaptively shorten and you don’t require as much ankle ROM. But then you take your shoes off and walk, go up your stairs, squat down to get things around the house etc. This is where people have issues. Not only at the foot/ankle but all the way upstream at other joints



Ankle ROM is incredibly important, and walking on a ramped surface all the time is incredibly unnatural. So do yourself a favour and spend less time in heeled footwear or get rid of it altogether


The Foot Collective is a group of Canadian physical therapists on a mission to help humans reclaim strong, functional and painfree feet through foot health education.

The Foot Collective are empowering people with the knowledge they need protect their feet from the dangers of modern footwear and the guidance to fix their own feet.

http://www.thefootcollective.com

BEYOND BIOMECHANICS BY DR. EMILY SPLICHAL

The following post appeared on the Evidence Based Fitness Academy (EBFA) fitness blog on February 6, 2018 under the title Beyond Biomechanics | Addressing Foot Pain with Sensory Stimulation (1.).

I have reproduced the post with the kind permission of Dr. Emily Splichal under the title Beyond Biomechanics by Dr. Emily Splichal because her emphasis on the role of sensory stimulation of the plantar foot on foot, lower limb and function of the entire body has both direct application to and implications for, skiing.

I have a theory on what I call The NABOSO Effect that explains how I think NABOSO insoles improve dynamic stability in the biokinetic chain that I will discuss in a future post. I have been testing NABOSO 1.0 and 1.5 for months.


Beyond Biomechanics | Addressing Foot Pain with Sensory Stimulation – by Dr. Emily Splichal

I want you to picture a human foot.   Now picture a person standing barefoot, and then walking barefoot.   Do you see the foot striking the ground and flexing under impact, only to re-stabilize and push off just a few milliseconds later?

Often times when we think of human movement we can’t help but to be drawn to the thought of joints moving and muscles contracting.   Or in the case of foot function we are quick to consider the mechanics of flat feet, high arches, pronation and supination.   However when we delve deeper into the science of human movement there is more than meets the eye.

The Two Sides of Foot Function

When I teach on behalf of EBFA Global or speak to my patients I always emphasize that there are two sides to foot function (and dysfunction) – biomechanical and neuromuscular.    Now both play an important role in foot function which means that both must be appreciated – however to solely treat foot pain with just one belief system in mind is inherently flawed.

In most Podiatric Medical Schools we are taught foot function and foot pathology solely from a biomechanical perspective.

This means that every patient is tested for foot mobility and told to stand statically to determine arch height and foot type.   Based on this foot-focused biomechanical assessment and foot classification system the patient’s cause of injury and treatment protocol is determined.   Some of the favorite treatment recommendations include motion-controlled footwear and custom-posted orthotic both of which are prescribed with the hopes of controlling foot-focused biomechanics and thereby reducing their foot pain.

Beyond Biomechanics

The other side of foot function is one that is driven from a neuromuscular perspective and integrates the science of sensory stimulation and fascial systems.   In the case of neuromuscular function every patient would be assessed for sensitivity of plantar mechanoceptors as well as co-activation patterns between the foot and the core.  The role of minimal footwear, myofascial releasing, breathing patterns and compensation patterns more proximal would all be considered.

So which is more appropriate?  Well it depends.   In certain cases there will be a stronger argument towards a more biomechanical influence and in others it is more sensory.  This means it really is a marriage between the two approaches that provides the greatest patient outcome.

Sensory Stimulation in Foot Pain

My practice and Podiatry career is built around bringing an awareness to the important role sensory stimulation has on foot function and foot pain.

With every step we take impact forces are entering the foot as vibration.  This vibrational noise stimulates unique mechanoceptors on the bottom of the foot and is used to coordinate the loading of impact forces through coordinated contractions of the intrinsic (small) muscles of the bottom of the foot.   This co-contraction leads to a stiffening or strengthening response of the foot.

Researchers such as Nigg et al. and Robbins et al. have demonstrated a direct relationship between sensory stimulation of the plantar foot and intrinsic muscle strength concluding that one is necessary for the other.   This means that if our footwear or orthotics disconnect us from sensory stimulation – as in the case of cushioned footwear – this can actually weaken our foot making us susceptible to plantar fasciitis, Achilles tendinitis and stress fractures.

Beyond Vibration Stimulation

Vibration stimulation is an extremely important sensory stimulation that enters our foot however it isn’t the only stimulation.   Another important stimulation is the ability for our foot to determine texture and if a surface is rough or smooth.   This information is used to help maintain dynamic balance (think walking on ice).

Enter the merkel disk mechanoceptors.   These superficial sensory nerves are used to determine what’s called 2 point discrimination which is translated to roughness or the texture of a surface.  Surface texture and insole texture is one of the most studied aspects of foot stimulation and posture or gait.  From decreased medial lateral sway in patients with Parkinson’s or MS to reduced prefrontal cortical activity in atheltes post-concusion the applications are promising!

One area that hasn’t been focused on for sensory stimulation and foot function is foot pain.  I am here to change the awareness around this concept and share the powerful application of sensory stimulation and foot pain.

As we mentioned earlier sensory stimulation of the foot leads to a contraction of the intrinsic muscles of the foot.   Intrinsic muscle contraction is not only a criticial step in the damping of impact forces but has also been shown to increase the medial arch and build co-activation contractions in the core.

 The Evolution of Textured Insoles

In October 2017 Naboso Technology launched the first-ever commercially available textured insole!   Naboso Technology essentially brought the science of touch and years of textured insole research to the market place giving new hope to people with foot pain.

Available in two strengths – Naboso 1.0 (1mm texture) and Naboso 1.5 (1.5mm texture) Naboso Insoles are designed to be worn without socks (or at the most very thin socks).  They fit into all footwear, are freely movable in all planes of motion and are only 3mm thick.

FROM THE GROUND UP

Are you barefoot strong?


Learn more about the power of texture! – http://www.nabosostechnology.com

  1. https://barefootstrongblog.com/2018/02/06/beyond-biomechanics-addressing-foot-pain-with-sensory-stimulation/

 

WHO NEEDS FOOTBEDS? NO ONE

There are some who can benefit from footbeds or orthotics and some who do actually need them. But these groups are the rare exception. And they are unlikely to be skiers.

Orthotics. The pros / cons of orthotics in today’s society!

In a recent YouTube video (1.), Podiatrist & Human Movement Specialist, Dr Emily Splichal, explores the concept of orthotics and their role in today’s society. Dr. Splichal doesn’t pull any punches when she says:

“…..I have been through the conventional podiatric school and been fed pretty much the bullshit from podiatry of how every single person needs to be in orthotics, that our foot is not able to support itself without orthotics……if we do not use orthotics our foot is going to completely collapse  and you are going to lose your arch…….”

“……Our foot is designed to support itself. If we actually needed orthotics, we would be born…..we would come out of the womb, with orthotics on our feet.”

Meantime, The Foot Collective  asks (2.) Are you promoting weak feet?

  • Anything you use for artificial support at the feet (footwear with arch support & orthotics) your brain takes into account and accommodates for it.
  • That means if you provide your foot support your brain shuts down the natural arch supporters to reduce un-necessary energy expenditure.
  • Stop using support to help with pronation and understand why your feet pronate in the first place – because they are weak.
  • Strong feet = strong foundation = strong body.

The Real Source of Support for the Arch

Ray McClanahan, D.P.M. offers a perspective on the issue of Arch Support in his post on the CorrectToes blog (3.)

Are Custom Footbeds and Orthotics better than stock insoles?

In his post of August 20, 2017, Custom Foot Orthotics; No Better Than Stock Insoles (4.), Rick Merriam, of Engaging Muscles, explores the issue of orthotics in depth.

Prior to being told that supportive insoles are the way to go, I think it’s safe to say that all of those people didn’t know what they didn’t know.

The erroneous assumption that every skier needs footbeds or orthotics was made at a time when little  was known about the function of the foot and lower limb, especially in late stance. I was one of those who didn’t know what I didn’t know when initially when down the ‘the foot needs to be supported in skiing’ road up until I realized what I didn’t know and took steps to acquire the requisite knowledge.

Footbeds; is anyone checking what they do?

In 2000, I formed a company called Synergy Sports Performance Consultants (5). Synergys’ product was high quality information. One of my partners, UK Podiatrist, Sophie Cox, was trained by Novel of Germany and was one of the few experts in the world at that time on the Pedar system. Synergy did not make and/or sell footbeds or orthotics. Instead, we checked the effect of footbeds on skier performance. We performed a quick footbed check for a minimal fee of $20 using the sophisticated Novel Pedar pressure analysis technology.

Synergy was one of the first companies in the world to use the Novel Pedar pressure analysis system synchronized to video to acquire data on skier performance and analyze the captured data.  The Synergy team with diverse expertise studied the effect of ski boots and custom insoles on skier performance and identified functional issues in the body that needed to be addressed. It was a common finding that custom footbeds were significantly compromising skier performance, especially the ability to create the necessary platform under the foot on which to stand and balance on the outside ski.

Synergy offered a comprehensive 5 Step Performance Program that started with a footbed check. A key component was item 2., the Biomechanical Check.

With increasing recognition of the negative effect of most footwear on the user and criticism of the unproven claims made for footbeds and orthotics coming hard and fast, credibility in skiing is rapidly going downhill. It is time for proponents of custom insoles for ski boots to support their claims with solid evidence, especially evidence supported with data acquired during actual ski maneuvers. The technology to do this has existed since at least the year 2000.


  1. https://youtu.be/CIRf9WHmMXI
  2. http://www.thefootcollective.com
  3. https://www.correcttoes.com/foot-help/articles-studies/arch-support/
  4. http://www.engagingmuscles.com/2017/08/20/custom-foot-orthotics/
  5. DIGITAL SALVATION FOR THE SOLE [BACK TO THE FUTURE] –  http://wp.me/p3vZhu-24g

ADDENDUM TO THE ORIGINS OF KNEE ANGULATION

The intent of my last post was to create an awareness of the lower limb alignment indicative of stability and how a lack of stability, whether intrinsic or caused by footwear, especially ski boots, will cause a skier to default to the use of knee angulation in what will be a failed attempt to hold the edge of the outside ski.

A skier will be unable to develop the requisite biomechanics to balance on their outside ski if they lack stability in barefoot monopedal stance under the minimal challenges associated with a flat, level unperturbed surface. If they lack lower limb/pelvic stability, there could endless combinations of causes which is why I listed a number of resources to help address this deficiency.

If a skier/racer exhibits good to excellent  stability under this basic test and they become unstable with the addition of any form of footwear, it suggests, but does not unequivocally prove, that the footwear is the cause. In more 4 decades of working with skiers and racers at all levels, I have consistently found that I can turn monopedal stability off and on at will. That I can do this without limitation, is indicative of cause and effect. In the 2 world class racers I am presently working with, even a small change in a liner or the over-tensioning of a shaft buckle or power strap has an immediate and noticeable effect on outside limb/pelvic stability and balance.

A key exercise I like to use with racers and elite skies I am working with is the vertical stacking exercise shown in the graphic below. This exercise is performed by starting from bipedal stance with the feet stacked under the heads of the femurs and the head and torso vertical and then making fluid arcing movement of the COM over the ball of the big toe while keeping the torso and head stacked vertically and the pelvis and shoulders horizontal as indicated by orange vertical and horizontal references in the graphic below. The torso should be aligned with the transverse or frontal plane, square with the foot.

A lack of stability in the biokinetic chain is typically evidenced by a drop of the opposite side of the pelvis and a leaning in the opposite direction of the torso and/or the head or both. While this reduces the load on the pelvis side of the  leg it creates a myriad of issues. Inside hip drop will cause the inside leg of a turn to assume the load as the skier inclines thus creating further instability on the outside leg.

Elite skiers and racers like Shiffrin are able to get over it (find stability on their outside foot and ski) in milliseconds. This enables them to retract the inside foot and ski with knee flexion as they incline into a turn similar to the mechanics cyclists use when they corner; outside leg extends, inside leg retracts.

The vertical stacking exercise is best performed in front of a mirror.

NABOSO PROPRIOCEPTIVE STIMULATION INSOLES

For several weeks, I have been testing the first-ever small nerve plantar proprioceptive stimulation insole technology called NABOSO, which means “barefoot” in Czech. The surface science technology was invented by Dr. Emily Splichal and is being marketed by her in conjunction with NABOSO yoga mats and floor tiles.

Introducing Naboso Insoles by Naboso Barefoot Technology. Get ready to experience what it truly means to move from the ground up with the first-ever small nerve proprioceptive insole to hit the footwear industry.

The skin on the bottom of the foot contains thousands of (small nerve) proprioceptors, which are sensitive to different stimuli including texture, vibration, skin stretch, deep pressure and light touch. When stimulated these proprioceptors play an important role in how we maintain upright stance, activate our postural muscles and dynamically control impact forces. – Dr. Emily Splichal

http://nabosotechnology.com/about

Dr. Emily Splichal goes on to state:

The skin on the bottom of the foot plays a critical role in balance, posture, motor control and human locomotion. All footwear – including minimal footwear – to some degree blocks the necessary stimulation of these plantar proprioceptors. The result is a delay in the nervous system which can contribute to joint pain, compensations, loss of balance and inefficient movement patterns.

Naboso Insoles are backed by surface science and texture research – and have been shown to not only improve balance but also positively impact gait patterns, ankle proprioception and force production in athletes.

Dr. Splichal stresses that:

This (NABOSO insole) is an insole providing proprioceptive and neuromuscular stimulation – it is not an orthotic providing biomechanical control.

http://nabosotechnology.com/naboso-insoles/

The principle proprioceptive neural activity associated with balance responses occurs across the plantar plane. It is strongest in the 1st MPJ (big toe joint) and big toe.

Dr. Splichal cites studies that found that textured insoles increased the activity of receptors in the plantar surface of the feet with a significant, immediate effect seen in the outcome measures of static (weight bearing) and dynamic (weight symmetry index, strength symmetry) in balance tests  as well as in gait symmetry (single support and swing phases). Thus, the proprioceptive stimulation benefit of textured insoles is carried over into footwear without textured insoles. I have noticed a significant improvement in  plantar proprioceptive sensitivity when barefoot or when my feet are not bearing weight. It is as if my feet have been put to sleep by a local anesthetic which has worn off.

Dr. Splichal’s information on NABOSO states that for the first time ever it is now possible to bring the power of barefoot science and plantar proprioceptive stimulation to all footwear – regardless of support, cushion or heel toe drop.

Assuming a NABOSO is trimmed, if necessary, to fit a shoe, there will be a positive effect on plantar proprioceptive stimulation. But my experience to date has been that the plantar proprioceptive stimulation will be much more pronounced in a minimal, zero drop shoe with adequate width for fascial forefoot tensioning and correct alignment of the big toe. I have experienced the best results with NABOSO in the Xero Prio shoe with the Lems Primal 2 and a Vivobarefoot model, close seconds.

The photo below shows the Xero Prio (blue-grey) with the Lems Primal 2 (black).

Both shoes have thin soles with low resiliency (the material compresses very little). The soles are also very flexible, an important quality. The sole wearing qualities of the Xero are excellent. The Xero Prio has become my all around minimal shoe. I use it for cycling on my mountain bike fit with large flat platform pedals.

The photo below is of the NABOSO insole for my left shoe.

Initially, NABOSO insoles are perceived, but not uncomfortable. After a time, shoes feel strange without them.

Over several weeks, I have done many tests of different shoes and insoles where I compare cushioned, standard insoles to NABOSO and different shoes with and without NABOSO as well as one-on-one comparisons with different shoes on each foot. After an initial walk in period, if I remove a NABOSO insole from one of my Xero Prios, it feels as if sole of the foot with the Xero without the NABOSO is signicantly less sensitive.

The most significant aspect of trying NABOSO insoles in different shoes is that it immediately becomes apparent just how bad some shoes are. The more cushioning, the narrower the fit and the greater the heel to toe elevation of the sole, the worse the shoe feels. For example, when I compared the Xero Prio with zero drop to a Nike Free with a 5 mm drop, I immediately sensed a pronounced negative effect on my posture and muscles of my legs, especially my glutes.

A Game Changer?

Prior to NABOSO, footwear companies could make shoes that have a negative affect on posture, balance and gait because it could be argued that the benefits of protecting the soles of the feet from mechanical damage outweigh any negative effects on balance and increased susceptibility to falls and injury. But the criteria for product liability is that a product must minimize, but not necessarily eliminate, the risk of injury to the consumer. Studies of textured insoles and even thin, low resilency soled footwear have shown dramatic improvements in balance and gait while reducing the risk of falls and potential injury. The inescapable conclusion is that footwear that reduces balance and the efficiency of gait while increasing the risk of falls and potential injury fails to meet this standard. This raises the question, “Will product liability litigation in footwear be the “next shoe to drop?””

NABOSO in  Ski Boots?

I have not yet had an opportunity to test NABOSO ski boots. But 2 racers I am working with are using NABOSO in zero drop minimal shoes. Stay tuned.

 

THE MECHANICS OF BALANCE ON THE OUTSIDE SKI: PRESS AND POINT THE BIG TOE

A widespread perception appears to exist within the skiing community is that the ability to hold a ski on edge by using the leg to exert force against the side of the stiff shaft of a ski boot and staying upright and not falling, equates with good balance. This ingrained perception presents a challenge in terms of communicating how the world’s best skiers create a platform under the body of the outside ski that they can stand and balance on using the same processes that we all use to stand and balance on a hard, flat level surface.

Last ski season, I developed simple cue to help skiers find the right mechanics and biomechanics as the new outside ski goes flat between edge change and then rolls into the turn on its new inside edge.  At ski flat, if a skier has the right stance, they should feel strong pressure under the ball and the big toe. As the skier extends and inclines into the new turn, the outside leg should be rotated into the turn to point the big toe in the direction of the turn. Hence the cue, press and point the big toe.  This pressure under the ball of the foot and big toe should be maintained through the turn phase until it is released by the transfer or weight to the inside (uphill) ski at the start of the transition to the inside. The strong pressure under the ball of the foot and the force that presses the big toe down flat is passively created by a strong stance, not conscious effort.

The Reverse Windlass

The pressure under the big toe is created by what is called the Reverse Windlass Mechanism. This naturally happens in the late phase of stance when walking barefoot. But wearing shoes with raised heels and cushioned insoles makes it impossible for the Reverse Windlass to function. When the Reverse Windlass is lost, it must be re-acquired by being barefoot as much as possible and walking, running and training in zero drop, thin soled minimal shoes. In some cases, people have to learn to walk naturally by rehearsing the action.

There is an excellent YouTube video by Teodoro Vazquez on Blog del Runner  called Windlass Mechanism and Running Biomechanics – https://youtu.be/y_8SrufgmDk. Vazquez describes the 3 phases of the windlass mechanism, Active (Activo), Reverse (Inverso)  and Passive (Pasivo). Although the video is directed at running, the primary concepts have direct application to skiing and ski technique. The reverse windlass is activated by the weight as shown in the graphic below from Vazquez’s YouTube video.
 This tensions the arch of the foot and presses the big toe down.
As the shank angle increases, the soleus muscle goes into isometric contraction and arrests further shank movement. The results in a heel to forefoot rocker action that dramatically increases the down force under the ball of the foot and the big toe. What I call the Spinal Reflex or SR Stance maximizes the down forces.

It is important that when the big toe (aka Hallux) is pressed down flat, the ball of the foot and big toe feel like one. When the big toe is pressed down properly, you should feel your glutes tighten. The leg you are standing on should be straight and the knee pointed straight ahead.

An important muscle in the Reverse Windlass is the Flexor Hallucis Longis or FHL. When the soleus goes into isometric contraction, the FHL is tensioned. This stabilizes the foot and knee by rotating them away from the center line of the body.

Things that prevent the Reverse Windlass

1. A condition called Hallux (big toe) Valgus
2. Narrow shoes and especially shoes with a pointed toe box.
3. Ski boots, especially ski boot liners.
4. Shoes with elevated heels, cushioning and toe spring (toes raised up). Note: A small amount of ramp angle is necessary for the SR Stance.
5. Footbeds and Insoles.
In my next post, I will discuss fixes to enable and/or restore the Reverse Windlass.

INTRODUCING THE FOOT COLLECTIVE

The Skier’s Manifesto places a high priority on foot function and exercises that make feet strong and healthy. (THE IMPORTANCE OF STRONG HEALTHY FEET IN SKIING).  There is a rapidly emerging camp of medical professionals and trainers aligned with this cause who offer excellent articles on this subject. One such group is TheFoot Collective – http://www.thefootcollective.com.

TheFoot Collective has kindly given me permission to repost material from their blog on the Skier’s Manifesto. The graphic below is from the home page of TheFoot Collective.

What is the Foot Collective?

The Foot Collective is a group of Canadian physical therapists giving people back control over the health of their feet through education. Most modern day humans have poorly functioning feet and our mission is to spread the truth about footwear and give people the information needed to independently restore their own feet.

The collective exists to spread awareness of the importance of foot health and to provide quality advice on restoring proper foot function.

Foot problems have reached epidemic levels and the solution is simple: Quality foot health education to help people fix their own feet.

There’s a big problem with modern footwear

The modern shoe is harming the human foot. Footwear companies are creating products to make money, not in the interest of foot health and its slowly killing our feet. We’re here to spread the truth about footwear.

Most footwear today has an elevated heel, narrow forefoot and a slab of foot numbing cushioning between your foot and the ground below you.

Your feet are magically designed body parts with the primary purpose of sending your brainsignals about the ground below you. When they get compressed and are prevented from sensing the ground because of cushioning, they lose their ability to function and create nasty upstream effects for our bodies.


The kind of shoes you wear daily, especially the type of shoe you train in, affects how your body functions in skiing. Cushioning and cushioned insoles are especially bad. This is a recent post on the TheFoot Collective.

THE DANGER OF HEELED FOOTWEAR
👣👣
wearing a shoe with an elevated heel might seem harmless but it has real effects on your posture upstream. These postural changes change how your body moves by making certain muscles more dominant (quads especially) and others weak (glutes)
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Over time, heeled footwear is a big culprit for knee problems and tight ankles so avoid them whenever you can. Finding a zero drop flat shoe can be quite difficult but taking the time to find one makes a massive difference in your joint health and movement patterns
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Most modern day running shoes and dress shoes have this nasty heel lift so beware of the consequences and transition to zero drop barefoot footwear. Your body will thank you
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I have been testing different brands of minimal shoes; zero drop, thin flexiable, low resilency soles, for the past few months and will posting on this issue soon. For reasons I will explain in future posts, it appears as if a small amount of positive toe down ramp (aka drop) – approximately 2.5 degrees, is important to a strong stance in skiing. But my regular footwear is all minimal, zero drop.