Stance

THE MECHANICS OF BALANCE ON THE OUTSIDE SKI: WINDLASS POWER

Two factors can prevent a skier from being able to develop a platform under the body of the outside ski on which to stand and balance on during a turn using the same processes used to balance on one foot on solid ground:

  1. The biomechanics of the foot and leg have been compromised by traditional footwear and,
  2. The structures of the ski boot, especially insoles, footbeds, orthotics and form fit liners, are interfering with the foot to pelvic core tensioning of the biokinetic chain that starts in the forefoot.

The torsional stiffening of the ankle and knee joints resulting from fascial tensioning of the biokinetic chain is fundamental to the ability to create a platform under the body of the outside ski by internally rotating the outside leg from the pelvis. It may sound complicated. But it is actually quite simple. Once learned, it can become as intuitive as walking.

The best method I have found to appreciate how ski boots, custom insoles and form fitting liners can affect the function of the feet and even the entire body, is do a series of exercises starting with the short foot. The short foot helps to assess the ability to harness the Windlass Power associated with the big toe. Once proper function has been acquired in the foot and leg, a skier can go through a methodical, step-by-step process to assess the effect of each component of the ski boot on the function of the feet and legs.

The latest edition of Runner’s World (1.) reports on a study done by a team at Brigham Young University that compared the size and strength of the foot’s “instrinsic” muscles in 21 female runners and 13 female gymnasts. Gymnasts train and compete in bare feet.

The researchers found:

Of the four muscles measured with ultrasound, the gymnasts were significantly bigger on average in two of them, with no difference in the other two. The gymnasts were stronger in their ability to flex their big toe, with no difference in the strength of the second, third, and fourth toes.

Although balance is important in all sports, it is especially critical in gymnastics. So it is significant that study found that the big toes of the gymnasts were stronger than the big toes of the runners.

Until recently, I found it much easier to balance on my left leg than my right leg. The big toe on my left foot was noticeably larger than the big toe on my right foot and the big toe on my left foot was aligned straight ahead whereas the big toe on my right foot was angled outward towards my small toes. This misalignment had pushed the ball of my foot towards the inside of my foot causing a bunion to form on the side, a condition known as hallux valgus. I now understand why I could balance better on my left foot than my right foot.

The muscle that presses the big toe down is called the Flexor Hallucis Longis (FHL). It is inserted into the last joint of the big toe where it exerts a pull that is linear with the big toe and ball of the foot. When the arch is maximally compressed in late stance, the Flexor Hallucis Longis is stretched and tensioned causing the big toe to press down. It’s insertion on the upper third of the fibula causes the lower leg to rotate externally (to the outside). When stretched, the FHL acts in combination with the Posterior Tibialis to support the arch. Footwear that prevents the correct alignment of the hallux weakens the arch making it more difficult to balance on one foot; the foot pronates unnaturally.

Going mostly barefoot for the past 10 years and wearing minimal type shoes for the past 6 years, made my feet stronger.  But it had minimal effect in correcting the hallux valgus in my right foot. It was only after doing the exercises in the links that follow, such as the short foot, that the big toe on my right foot became properly aligned and grew in size. It is now the same size as my left toe and I am able to balance equally well on both feet. The problem with ski boots and most footwear, is that they can force the big toe into a hallux valgus position while preventing the forefoot from splaying and spreading naturally weakening the arch and significantly impairing natural balance.

In the early 1970’s, when the then new plastic ski boots were making a presence in skiing, research on human locomotion was in its infancy. Studies of the effects of sports shoes on human performance were virtually nonexistent. The only technology available back then with which to study the biomechanics of athletes was high speed (film) movies. Ski boot design and modification was a process of trial and error. Many of the positions that predominate even today were formed back then.

As methodologies began to develop that enabled the study of the effect of sports shoes on users, biomechanists and medical specialists became convinced that excessive impact forces and excessive pronation were the most important issues affecting performance and causing or contributing to injury. I suspect that biomechanists and medical specialists arrived at this conclusion even though there was little evidence to support it because it seemed logical. Soon, the term, excessive pronation became a household word. The perceived solution? Arch supports, cushioned soles, motion control shoes and a global market for arch supports.  This appears to have precipitated an assumption within the ski industry that the feet of all skiers needed to be supported in ski boots and pronation, greatly restricted, or even prevented altogether. Even though no studies were ever done that I am aware of that demonstrated that pronation was a problem in skiing, support and immobilization became the defacto standard. Custom footbeds, orthotics and form fitted liners became a lucrative market.

As the support and immobilize paradigm was becoming entrenched in skiing, studies were increasingly concluding that, with rare exceptions, excessive pronation, is a non-existent condition with no pathologies associated with it and that the role of impact forces was mis-read. Today, it is increasingly being recognized that interference to natural foot splay and joint alignment of the big toe by the structures of footwear, causes weakness in the foot and lower limbs through interference with the natural processes of sequential fascial tensioning that occurs in the late stance phase. But the makers of footwear and interventions such as arch supports, have been slow to recognize and embrace these findings.

A key indicator of whether a skier has successfully developed a platform under the outside ski with which stand and balance on, is the position and alignment of the knee in relation to the foot and pelvis as the skier enters the fall line from the top of a turn. I discuss this in my post, MIKAELA SHIFFRIN AND THE SIDECUT FACTOR.

Best Surfaces for Training

A good starting point for the short foot and other exercises is Dr.Emily Splichal’s YouTube video, Best Surfaces for Training https://youtu.be/gvJjIi3h1Bs

Although it may seem logical to conclude that soft, cushioned surfaces are best for the feet, the reality is very different. The best surfaces to balance on are hard, textured surfaces. Dr. Splichal has recently introduced the world’s first surface science insoles and yoga mats using a technology she developed called NABOSO which means without shoes in Czech.

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 resulting in a delay in the response of the nervous system which can contribute to joint pain, compensations, loss of balance and inefficient movement patterns. I’ve been testing NABOSO insoles for about a month. I will discuss NABOSO insoles in a future post. In the meantime, you can read about NABOSO at https://naboso-technology.myshopify.com/products/naboso-insoles

Short Foot Activation

 

Short Foot Single Leg Progressions


  1. Here’s the Latest Research on Running Form – May 30, 2017
  2. Biomechanics of Sports Shoes – Benno M. Nigg

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
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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.

STANCE HACK: TUNE UP YOUR FEET

Biohacking Your Body with Barefoot Science

“…… hacking” or finding a way to more efficiently manipulate human biology.  This can include areas of sleep, nutrition, mental health, strength, recovery. (1)
– Dr. Emily Splichal – Evidence Based Fitness Academy

 

Last ski season, I developed some simple cues or hacks to help skiers and racers quickly find the body position and joint angles required to create the pressure under the outside foot with which to impulse load the outside ski and establish a platform on which to stand and balance on through the turn phase –  THE MECHANICS OF BALANCE ON THE OUTSIDE SKI: IMPULSE LOADING

The primary source of information that helped me develop these cues are the exercises developed by Dr. Emily Splichal. Her exercises also helped me to appreciate the extent to which traditional supportive footwear with raised heels and cushioned soles has damaged my feet and deadened the small nerves responsible for maintaining upright balance and the ability to initiate precise movement. Since implementing Dr. Splichal’s evidence based science, I am not only skiing at a level beyond what I considered possible, I am starting to walk naturally for the first time in my life.

The information contained in Dr. Splichal’s videos will challenge everything you know or thought you knew about what we have been conditioned to believe about our feet and the footwear we encase them in. Contrary to what we have been told, cushioning under the feet does not reduce impact forces on the lower limbs and protect them. Instead, it actually increases impact forces while slowing what Dr. Splichal refers to as the time to stabilization; the time required to stabilize, stiffen and maximally protect the joints of lower limb from impact damage – THE MECHANICS OF BALANCE ON THE OUTSIDE SKI: TIMING OF EDGE CHANGE

The Best Surfaces to Train On

A good place to start is to learn which surfaces are best to train on. Again, while it may seem logical and intuitive that surfaces with cushioning are best because they will protect the body from shocks, studies show the exact opposite to be true. Over time, support and cushioning in shoes can diminish the sensitivity of the rich small nerve matrix in the feet that acts as a neural mapping system for balance and movement. In her YouTube video, Best Surfaces to Train On (https://youtu.be/gvJjIi3h1Bs), Dr. Splichal discusses the effects of different surfaces on plantar small nerve proprioception and explains how barefoot training is a form of small nerve proprioceptive training designed to activate the plantar foot. Balance training is best done barefoot.

The Power of Plantar Proprioceptors

Watching Dr, Splichal’s webinar presentation Understanding Surface Science: The Power of Plantar Proprioceptors – https://youtu.be/t5AU-noqMFg will further your appreciation of the power of plantar proprioception.

First Stance Hack – Plantar Foot Release for Optimal Foot Function

Dr. Splichal’s 6 Minute Plantar Foot Release for Optimal Foot Function – https://youtu.be/zyrKgFwsppI will dramatically improve foot function.
Dr Splichal explains how to use RAD rollers (golf ball or other firm balls will also work) to optimize foot function by releasing tissues in the plantar foot by applying pressure to the 6 areas shown in the graphic below.
Dr. Splichal advises to focus on using a pin and hold technique  (not rolling the foot on the balls) to apply pressure to these 6 spots on each foot holding for about 20 seconds on each spot with each of the three different sized rounds for a total time of about 6 minutes. The foot release should be done 2 times and day and prior to each training session.
In my next post I will talk about the second Stance Hack: Pressing Down on the Big Toe to Impulse Load the Ski and Power the Turn

1.  https://barefootstrongblog.com/2017/04/28/biohacking-your-body-with-barefoot-training/

THOMAS’ THOUGHTS ON THE REPETILIAN BRAIN AND ITS EFFECT ON SKIER STANCE AND MOVEMENT

 

I started this blog with the objective of stimulating critical thinking on issues of skiing that would result in an intelligent, interactive dialogue. It appears as if this is beginning to happen as expressed in the critical thinking by Thomas in his comments on recent posts.

Thomas’ comments follow below with emphasis added in the form of underlined and bolded text by me.


This quote from W Hauser, P. Schaff, caught my eye.

“Many alpine skiers have insufficient mobility in their knees and ankle. The range of motion, particularly in the ankles, is much too small. This results in a static, stiff run. It does not correspond at all to the ideal of a wide range of mobility in the area of the knee and ankle, which was proposed and taught during early alpine ski lessons. Even the best diadactic (patronizing) methodology is not always successful in imparting to the student the full range of motion. The lack of proper technique seem so often is not due to a lack of ability, but to an unsatisfactory functional configuration of the shaft in so many ski boots. This is particularly true in models designed for children, adolescent and women.”

  • I would take a rather contrary view here and say the problem comes not from the boot design but a lack of technique. That is not because I disagree with Herr. Schaff.
  • The modern skiing didactic does not really teach the hard, strong, or tensioned arch which if I understand it correctly is only induced when a certain forward range of shank motion and COM is achieved.
  • This in turn sets up a chain reaction through the legs into the torso. Without this the skier can not attempt optimal form(s) or balance.
  • The arch concept is not widely taught or understood. Therefore there is not a demand for footwear that meets the basic requirements for optimal skiing.
  • Without this basic understanding it will be a matter of chance whether ski enthusiasts purchase or even know to adjust boots for full range of shank motion.
  • A key part of teaching stance technique has to become adjusting boot cuff for adequate shank range of motion. When I suggested to a student lessening cuff buckles, he reflexively tightened them. Ouch.
  • Once the body finds (if boots permit it) the strong arch, our neurology gravitates to your SR stance and presto all kinds of problems just go away including the back seat.

Rather disconcerting it all has to be reprogrammed after lunch.

This brings me back to a general question of safety with respect to equipment. Not is the equipment safe? But (is it) safe in terms of how the brain perceives safety (balance) and makes purchase decisions.

For example in skiing on one 190 cm ski and one 90 cm snowblade I notice that the 190 allows me to be way back without negative consequence. I had to really learn to keep balance on the strong arch of the 90cm snowblade. In a hockey stop the 90 snowblade flew out from under me up into the air! I remained upright because of the other ski’s long tail and the hard stop of the other boot. My reptilian (spinal reflex) brain reaction to the short snowblade was it was unstable and therefore dangerous.

The conclusion is when my brain tells me I am safe, I will want to ski all day long in really bad form with boots/skies designed to compensate for, well, bad technique. Therefore, neither would I likely ask other people to try the strong arch, SR, optimal range of motion cuffs, 90cm skies nor purchase lessons or equipment of like kind.

No one I ski with is willing to try the 90/long ski combo or the pair of 90s. My guess is because of their emotional reaction to imagining loss of stability; their brains will NOT permit them to even try.

These equipment usage and purchase decisions are occurring below the level of perception, consciousness. They are logical in terms of the reptilian brain’s safety hard wiring. I’m guessing this was the motivation for the student above to tighten (not loosen) boots because his brain equated more rigidity with security = safety.

If we want to ski better read this blog don’t listen to your reptilian brain anymore. Except when the speed and accuracy of these emotional reactions saves your life!

 

FOOTWEAR DAMAGED FEET

If you wear constricting and/or supportive footwear for any length of time, the odds are good that your feet will eventually suffer some form of damage. Based on my personal experience, the earlier you start wearing footwear as an infant and the more supportive and stiff the soles, the greater the odds that undoing any damage in the future will take an intensive, protracted effort.

Feet First

A good starting point in the ski boot set up process is a check of the most important and sophisticated component of equipment in the boot/binding/ski system, the human system, starting with the feet.

One of the first steps I took after I experienced difficulty skiing in the new, higher, rigid plastic ski boots after moving from low cut leather ski boots, was to make an appointment with a podiatrist to have my feet examined for problems. After an examination, I was advised that my feet did not have significant issues. In short, I had normal feet (normal, not natural).

Having eliminated foot problems as a factor (or so I thought), I suspected that my feet needed supplementary support in order to withstand the forces of skiing. So I made an appointment with a well-known sports podiatrist in Washington state and explained my situation. He prescribed semi-rigid orthotics for my feet for use in my running footwear and ski boots. The results fell far short of my expectations. I felt higher impact forces in running. In my ski boots, I could not hold an edge on anything other than soft pistes. I expected that it was a simple matter of adjusting to the orthotics. But after a period of time with no improvement, I stopped using them in any of my footwear, eventually discarding them.

Signs of Foot Damage

As I stated in my last post, my first footwear as an infant were narrow and stiff soled; marketed and promoted as ‘orthopedically correct’. That was the only type of footwear I wore in the early years of my life.

The photo below compares my left and right feet. The foot that I have more difficulty balancing on should be obvious. My right foot is less stable than my left foot because the claw toe deformation prevents the metatarsals of my foot from splaying especially in monopedal stance.

l-v-r

Eleven years ago I started going barefoot the majority of the time. Back then, the claw toe deformity was far worse, moreso in my right, than my left foot than shown in the above photos. These photos were taken a few days ago after months of exercises such as the short foot that are designed to strengthen and rehabilitate damaged feet by working with the whole body. I discovered that if the damage is severe enough, going barefoot may not be sufficient correct it.

The photo below compares my left foot is it looks today to the same foot with a corrective toe spreading device on the same called Correct Toes.

correct-vs-bare

Correct Toes were designed by sports podiatrist and elite distance runner, Dr. Ray McClanahan because he was unsatisfied with the inconsistent and temporary results offered through conventional symptom management techniques: orthotics, medication and/or surgery (www.CorrectToes.com). According to the brochure, Correct Toes provide the best results when worn in shoes and walked on so long as the shoes are wide enough to allow the toes to splay so the foot can properly assume the weight of the body in single leg stance.

One shoe that is wide enough to wear the Correct Toes in is the VivoBarefoot Gobi II WH shown in the photo below.

img_6602

The photo below compares the sole of the VivoBarefoot to a conventional slip on shoe. The blue bar shows the width of the conventional slip on compared to the width of the VivoBarefoot as indicated by the red bar.

vivo-vs-sandal

From a perspective of logic alone, it should be obvious that when one foot carries the entire weight of the body, the base of the foot should splay (expand transversely and longitudinally) so as to provide greater weight distribution and stability by increasing the base of support. The associated biomechanics of the support limb are infinitely more complex than splaying suggests. Preventing the base of the support foot from fully splaying at least partially explain why the majority of skiers, even at the World Cup level, are unable to ‘stand and balance’ on their outside ski in a turn as has been advocated for decades by the world’s best skiers.

Footwear that prevents the metatarsals and toes from fully splaying can cause the muscles that support the arches to weaken. When this happens, it is common for the muscles that flex toes to intervene in an effort provide support for the arch.

When the great (big) toe or Hallux is forced towards the outside the foot, as is common in footwear, especially ski boots, it can weaken the arch. When this happens, the head of the first metatarsal will usually shift inward (medially) creating a condition called Hallux Valgus. In response, the 2nd and 3rd toes, will intervene in an attempt to shore up the arch.

The left photo below shows a manipulated alignment of my great toe with the second digit severely plantarflexed in an attempt to shore up my arch. This is what both my feet used to look like until recently. Over time, the first knuckles of the second and third toes became deformed and frequently developed sores from pressing upward against the inner surface of my footwear.

abducted-hallux

Prolonged plantarflexion of my first four toes eventually led to my small toe moving underneath my 4th toe. The right photo above shows what my foot looks like after months of exercises, the use of minimal shoes and Correct Toes.

If damage to the feet has occured before ski boots are worn, adverse effects  are more likely because a compromised medial (inner) arch can result in excessive mobility in terms of the 3-dimensional movement of the elements of the foot. When a skier with this issue attempts is to stand and balance on the outside foot of a turn, the inside ankle and navicular bones can move inward and hang up on the inner wall of the ski boot shell.

As shown in a recent study, going barefoot will strengthen the muscles that support the arches of the feet . But going barefoot alone is unlikely to correct deformities such as claw toes. The feet are integral part of the whole body. Problems that show up in the feet can be caused by problems higher up the chain.

I prefer a holistic, systems approach using a number of complementary modalities to addressing issues in the feet or any part of the body.

In my next post, I will discuss the effects of densities and surface textures of different flat insoles. I will also start posting links to the rapidly growing camp of barefoot-minimal expertise. Here are but a few.

FEET FREEX – Jessi Stansland – http://www.feetfreex.com

EBA Fitness – Dr. Emily Splichal – www.youtube.com/user/EBFAFitness

Northwest Foot & Ankle – Dr Ray McClanahan – www.nwfootankle.com

Katy Bowman – Nutritious Movement – http://www.nutritiousmovement.com

THE SR STANCE: SURFACE EFFECTS

A good segue to continuing my discussion of the SR Stance is to provide a tool that will enable the assessment of the effect of different surface densities and textures and footwear, orthotics and generic insoles on the small nerve proprioceptors in the plantar foot.

Most people assume that cushioning under the plantar foot is a good thing; that it provides comfort and helps protect the foot from shocks. Who needs footbeds? Everyone. It’s only common sense. Everyone knows the foot is weak. It needs support. Except, that none of this is true.

“With thousands of plantar receptors, the foot is also a proprioceptive-rich structure, containing thousands of small nerves that are sensitive to every subtle movement we make. Our ability to walk, run or jump is all initiated through stimulation of these nerves on the bottom of the foot (aka the plantar foot).

“Because of the smaller diameter these plantar nerves are able to send signals faster to the Central Nervous System, creating faster response times”.

– Barefoot Strong by Dr. Emily Splichal

“80% of our plantar proprioceptors are sensitive to vibration”    – Nigg et al

“With small nerve receptors sensitive to stimuli such as texture, vibration, pressure and skin stretch, the skin on the bottom of the foot is unique when compared to the skin on the top of the foot or the lower leg.

“As soon as we put on socks, orthotics  or shoes we block these highly sensitive small nerves on the bottom of the foot.”

– Barefoot Strong by Dr. Emily Splichal

What Dr. Splichal says is true of any form of arch support. Ski boots are arguably the worst form of footwear for blocking the highly sensitive small nerves on the bottom of the foot.

As Dr. Splichal explains, the power of neuromuscular activation that enables precise balance and movement originates from the ground and moves upward through the plantar foot.

An easy way to impart an appreciation of how the stability, density and texture of surfaces under the plantar foot or structures such as insoles, orthotics, ski boots, liners or any form of footwear, affect stance, balance and movement patterns is by doing a series exercises on one foot starting barefoot on a hard level, stable surface, then adding different materials between the plantar foot and the supporting surface and assessing their effect on balance.

Dr. Splichal demonstrates a series of exercises in her EBFA YouTube Fitness group called Best Surfaces for Barefoot Training – https://youtu.be/gvJjIi3h1Bs

There are some issues with the quality of this particular video, especially as it ends and the volume increases dramatically. So use caution, especially if you are wearing earbuds or headphones. This issue aside, Dr. Splichal’s demonstration is spot on.

Reference Surface

The reference surface for establishing a baseline should be solid, stable, level and uniform. Texture is important. The worst surfaces for small nerve stimulation are smooth and glass like. Through experimentation, I have found that the best surface in my home is the concrete floor in the mechanical room which is coated with an epoxy paint with fine sand imbedded in it. The worst surface is the smooth laminate in the main living area. Tile in the entry hall with a slight texture is somewhere in between.

The photo below shows textured surface concrete on the left, smooth laminate on the right.

textures

Balancing on One Foot

Although balancing on one foot in a process of alternating single limb support is our basic mode of locomotion, most people seldom engage in prolonged balance on one foot. In order to ensure accurate assessment of surface effect, the move from balance on two feet to balance on one foot should be rehearsed. In my patents, I refer to these two states as bipedal and monopedal support.

Start by standing relaxed on both feet in an upright stance. Start moving the pelvis towards one foot. The movement of the pelvis should be in an arc that is sideways and forward as if the side of the pelvis on the support leg is moving diagonally towards the little toe.

As the pelvis moves forward, relax the ankle and allow the weight (pressure) to move to the ball of the foot. Keep a small bend in the knee as Dr. Splichal advises in her video.

Move back to balancing on two feet. Then repeat the balance exercise on the other side.

Repeat the exercise until you can quickly find stable balance on each foot and maintain it with minimal effort for at least 20 seconds. This may take time if the muscles that are being recruited are weak and/or unbalanced.

When you are comfortable balancing on either foot, try the exercise on different stable, hard surfaces and compare the effect of the different surface textures on balance.

You may want to try the same exercise on carpet if it is available.

A Word about Pronation

A campaign of misinformation has created a widespread perception that any amount of pronation is unnatural, even dangerous and should be prevented with a supportive insole or orthotic. Some experts have taken the position that a small amount of pronation is desirable but that it should be restricted to a specific amount controlled by an orthotic.

In a future post, I will expand on my earlier discussions of the 3 foot types. While it is correct that both pronation and supination are abnormal, the context of abnormal is in bipedal stance. From a perspective of basic trigonometry, the leg must adduct (move towards center of the body) about 6 to 7 degrees in order for the foot to be positioned under the centre of gravity. The foot must rotate an equivalent 6 to 7 degrees about its long axis in order for its tripod points to become compliant with the supporting surface.  STJ joint coupling produces an equivalent amount of internal rotation of the tibia about its vertical axis. Eversion/internal rotation is called pronation.

The absurdity of what amounts to an all out war on pronation should become apparent from viewing the stick man figure below from my patents.

FIG 23A - 23BSystematic efforts aimed at immobilizing the joints of the foot and leg in the ski boot, usually in neutral STJ, prevent skiers from assuming a balanced (read: pronated) position on the outside foot and ski ski thus ensuring the existence of an unbalanced moment of inversion/external rotation force. In addition, studies have shown that restraining the ankle in a tightly fitting ski boot increases laxity of the knee under closed chain whole leg rotation by approximately 30% over lesser forms of ankle constraint.

In my next post, I will discuss a series of exercises for assessing the effect of the components of the ski boot, including different liner components and interventions that support the arch of the foot.


Dr Emily Splichal is a Podiatrist and Human Movement Specialist.

She is the Founder of the Evidence Based Fitness Academy (EBFA) and Creator of the Barefoot Training Specialist, Barefoot Rehab Specialist and Bare Workout Certifications for health and wellness professionals.

Her book, Barefoot Strong is available in print and ebook formats.

http://evidencebasedfitnessacademy.com/faculty.html

THE SR STANCE AND TOTAL BODY CORE INTEGRATION

“Body tension follows fascial lines and the concept of tensegrity. The more tension created by the body, the faster you can stabilize joints, generate force and improve performance”

– Barefoot Strong by Dr. Emily Splichal

The word ‘tensegrity’ is an invention: a contraction of ‘tensional integrity.’ Tensegrity describes a structural-relationship principle in which structural shape is guaranteed by the finitely closed, comprehensively continuous, tensional behaviors of the system and not by the discontinuous and exclusively local compressional member behaviors. Tensegrity provides the ability to yield increasingly without ultimately breaking or coming asunder”

– Richard Buckminster Fuller –  Synergetics p. 372.

You can find many images of structures utilizing principles of tensegrity in a web search. The graphic below is of a model I made years before I had ever heard of tensegrity. Note the shear forces, Fs, resulting from compression-tension in the arches of the foot. The shear forces provide the reaction force for the isometric chain that sets up tensegrity.sr-tripod-demo

Isometric Contractions

“Vibrations are damped through isometric contractions.”

“Previous theories on impact forces and overuse injuries relied much more on eccentric muscle contractions and joint mobility. The research of Dr. Nigg from the University of Calgary has since challenged this concept.”

– Barefoot Strong by Dr. Emily Splichal

The SR Stance imparts a state of tensional integrity in the entire body in a bottom up manner emanating from the plantar foot and extending to the shoulders. The SR Stance configures the angles of joints of the ankle, knee and hip with the associated muscles in isometric contraction. The process of setting up a static preload in the Achilles tendon is actually setting up a state of isometric contraction in the first link of the isometric chain, the soleus.

Good Vibrations

“What we will soon find out is that it is not the impact forces that are the cause of injury; it is actually a flaw in how our body perceives and responds to these impact forces.”

“Although we associate and perceive impact forces as pressure, we actually perceive impact forces as vibrations. The vibrations caused by ground reaction forces are set at a certain frequency that our muscles are programmed to.”

– Barefoot Strong by Dr. Emily Splichal

By 1980, I had reached the conclusion that the forces required to constrain the foot to a ski must be localised on the dorsum of the foot and substantially perpendicular to the transverse aspect of the ski base in order to maintain a load reference with the plantar foot. Although I did not fully understand the implications, I had concluded that boot boards that were not integrated into the base of the boot shell acted as insulators of vibrations from the ski. Foam boot boards are especially bad because they damp vibrations.

At the time that I conceptualised the in-boot dorsum restraint system disclosed in US Patent No 4,534,122 (Aug, 13, 1985),   there were still significant voids in my knowledge. The device, in combination with a cast in place, torsionally and flexurally rigid carbon fibre boot board, was first used by Canadian Crazy Canuck, Steve Podborski, to compete and win on some of the most challenging downhill courses on the World Cup circuit. That he did this less than 4 months post reconstructive ACL surgery was nothing short of a miracle. Although I had based the technology on my untested theory that it might reduce stress on the knee by damping load-unload oscillation, I was both surprised and perplexed by Podborski’s ability to even ski with a knee in such a fragile condition, let alone with minimal pain or discomfort. I now know why. By sheer luck, it appears as if the components I had put in place in his boots must have had the correct vibration frequency to allow the muscles in his legs to damp vibrations and protect his knees.

THE EMERGING REVOLUTION UNDERFOOT

After centuries of damaging feet and causing  knee, hip and back pain with the associated suffering, an age of enlightenment is finally emerging with the potential to lift the artisan design of footwear, of which the modern plastic ski boot is arguably the worst example, out of the dark ages. That this is finally happening, hit home recently when I discovered the brilliant Dr. Emily Splichal and her book, Barefoot Strong.

Dr. Splichal’s teachings will challenge everything you THOUGHT (past tense) you knew. She confirmed and clarified concepts and theories that I have mulled over for decades. In reading her book, it was if a bright light  suddenly illuminated what had been cloaked for centuries in the darkness of ignorance.

Dr. Splichal has gracously given me permission to reproduce excerpts from her book. But she has done such superb job of articulating the subject matter that I would end reproducing the majority of her book if I were to reproduce every important statement. So I urge those who are reading this post to obtain a copy of Barefoot Strong so I can simply direct readers to the appropriate page and paragraph number in order to facilitate dialog.  Here are a few more passages from Barefoot Strong.

“What we will soon find out is that it is not the impact forces that are the cause of injury; it is actually a flaw in how our body perceives and responds to these impact forces”.

“Although we associate and perceive impact forces as pressure, we actually perceive impact forces as vibrations. The vibrations caused by ground reaction forces are set at a certain frequency that our muscles are programmed to.

“As we put on shoes, socks, orthotics we begin to block the plantar receptors, skewing our perception of how hard we are striking the ground”.

The problem? Shoes and even socks block the thousands of small receptors in the bottom (read: plantar aspect) of the foot. What’s worse? Cushioning and extra support in shoes decreases foot strength.

A perfectly fit, tightly constricting ski boot that applies force to all aspects of the foot and leg with arch supports or orthotics that block plantar receptors is the worst possible scenario. More than just circumventing the plantar receptors, it prevents the damping process by bypassing the foot and the portion of the leg encased within the structures of the boot shaft thus acting to transmit forces from the snow up the vertical column with no damping. This objective is clearly stated in patents of which the excerpt below is but one example:

“During skiing the sole of the ski boot is rigidly connected to the ski by a ski binding. As a result, the ski boot acts as an interface between the ski and the lower leg of the skier. In order for the reaction of the ski on the surface of the snow to be transmitted immediately and accurately to the lower leg, and conversely, for the control exerted by the skier on the ski via the lower leg and the interface also to be transmitted immediately and accurately, the foot and lower leg must be held perfectly snug by the boot.”

– US Patent No. 6026594A

Given the importance of tensegrity in stabilizing joints, generating force, improving performance but especially, protecting the structures in the foot and vertical column from injury, the current trend in making boot shafts more upright  to encourage skiers to ski in a more upright, relaxed stance should be deeply concerning especially in view of consistent claims that ski boots maximise energy transfer.

In my next I will discuss how footwear caused such long lasting damage to my feet as a child that I am only now through a protracted effort finally achieving a degree of normal foot function. After this post, I will continue to discuss Dr. Splichly’s work in the context of  THE EMERGING REVOLUTION UNDERFOOT that has  made mininal shoes a billion dollar and rapidly growing segment of the footwear industry.


Dr Emily Splichal is a Podiatrist and Human Movement Specialist. She is the Founder of the Evidence Based Fitness Academy (EBFA) and Creator of the Barefoot Training Specialist, Barefoot Rehab Specialist and Bare Workout Certifications for health and wellness professionals.

I am forever indebted and grateful to Dr. Emily Splichal for the wealth of knowledge she has transferred to me that have renewed my passion and made my efforts of the past 40 years worthwhile. Thankyou Dr. Emily Splichal.

Her book, Barefoot Strong is available in print and ebook formats.

http://evidencebasedfitnessacademy.com/faculty.html

http://www.ebfaglobal.com

DEDICATION in Barefoot Strong

“For those who have the courage to step out

of their comfort zone and challenge the

accepted.

Alway’s push past life’s challenges, fulfill your

dreams and live a life full of passion”

To which I would add……… live a life full of passion and purpose.

Do not simply aspire to be

Be