ski boots

DIGITAL SALVATION FOR THE SOLE [BACK TO THE FUTURE]

“Any sufficiently advanced technology is indistinguishable from magic.”  – Clarke’s Third Law

Conspicuous hardly begins to describe what I was feeling.  In the early morning rush of skiers grabbing a quick caffeine rush at the Wizard Grill, amid tables full of Ski School twinks waiting to see whether they were going to have any work for the day, an attractive woman was carefully stringing computer cables up the inside legs of my ski pants.  Things like that draw attention even at the base of Blackcomb on a Monday morning.

One end of the cables were attached to pressure sensing insoles in my ski boots, the other to a data recording box I was trying to figure out exactly were to attach.  About the size of an epic Michener paperback, it was just too big to slip into any of my pockets.  Finally clipped to the waist of my pants, it was, in turn, coupled to a high-powered flash unit strapped to my arm, both of which were fired by a button left dangling pretty much nowhere.

Robocop.  I couldn’t get the image out of my head, although at least one person who asked what all the hardware was about accepted my answer that it was a control mechanism to power my artificial leg.

David MacPhail grabbed the digital video camera and we headed up Blackcomb to take some measurements.  Dave — who I’d been working with to document some background on the Rise boot he’s been developing — had only recently launched Synergy Sports Consultants.

I wasn’t clear where exactly he was taking me or what we were going to accomplish, but a more willing guinea pig would have been hard to find.  In the nether world of ski theory, and more particularly in the areas of skiing biomechanics and modeling, Dave MacPhail is riding the cutting edge.  His work with National Team skiers and his understanding of exactly happens to the human body when it straps on a pair of skis has brought him an international reputation as an authority in the field.

On a clear slope under the Solar Coaster, Dave skied ahead to set up the video shot.  Sophie — who’d wired me up — rechecked the cable connections, set a baseline measurement for each of my unloaded feet and told me to point the flash unit down the hill at the camera.

As they signaled their readiness to each other, Sophie fired the flash and told me to ski down toward Dave.

Making my best ski school turns, I skied for the camera.  We repeated the process a few times and then we went back down to the Daylodge to…well, I wasn’t sure to do exactly what.

What, turned out to be mind blowing.  The unit strapped to my waist was a Pedar foot pressure data recorder from the Novel company of Munich, a techy little piece of equipment that, until last year, was the size of a small desk.  On a PCMCIA flash card, the unit was capable of recording about 10 minutes worth of data.  Fed by 80 pressure sensors arrayed throughout the insoles in my boots that each took 50 measurements per second, the Pedar tracked pressure across time as my feet worked to move me like a skier.

Downloaded onto a laptop computer and run through the company’s software, the data could be displayed as images of my left and right foot, colour-coded across the sensing mechanisms to display the changes in foot pressure as I made turns.  With lower pressure readings showing up as black squares and higher pressure lighting up bright pink, the readout was a moving kaleidoscope of colour as it played back my runs down the mountain.


On each colourful foot profile, a small dot traced a red line showing my centre of pressure at any moment in time.  A good skier using foot pressure the way they’re supposed to, would, over the course of a run, track a red line from the ball of their foot back toward their heel.  The track would be true and relatively straight with few variations.  That’s what the tracing on my right foot looked like.  The track of pressure of my left foot looked like someone who had never seen an Etch-A-Sketch grabbed both knobs and started twisting them randomly.

The difficulties showing up in my left foot readout were verified when Sophie explained the graphic display at the top of the screen.  “This line graph shows change in pressure over time for each foot.  When you make a good turn, like you’re doing with your right foot, the graph of pressure shoots up dramatically at the start of the turn, drops down slightly to a plateau, then falls away as you unweight the foot at the beginning of the next turn.  Your left foot comes on very gradually.  Something’s blocking your foot function,” she explained.

The final diagnostic piece of the puzzle — at least as far as the technology end of things went —was put in place when Sophie downloaded the images from the digital video camera and synchronized them with the Pedar display.  There I was, making graceful turns and there was the readout of what my feet were doing — or not doing, as it turned out.

“Neat,” I said.  “Now what?”
“Now you find out what Synergy is all about,” said Dave.

Synergy — small “s” — is about joint action of different substances producing an effect greater than the sum of the effects of all the substances acting separately.

The whole being greater than the sum of the parts. 

In a theological context, synergy is a doctrine that human effort cooperates with divine grace in the salvation of the soul.  I’ve often thought of skiing as a salvation of the frozen Canadian soul and certainly a day in the high alpine making perfect turns in all conditions is as close to divine grace as most of us will ever come.  But it was the more secular meaning of the word Dave had in mind in naming the company.

“The whole concept of Synergy probably came into my mind 25 years ago.  I started thinking about something called bio-integration, bringing people with different important skills together to work holistically on making your body work right.  Five years ago, we couldn’t have launched Synergy because the technology wasn’t quite there.  We needed more sophisticated software and I could see the time coming closer to when we’d reach a point where a lot of things in athletics that are mysteries now were going to be revealed by being able to plug in sensors at key points of interface.  Now, we’re starting to get there.”

But data is just data without something to make it sing.  And that’s where the principals of Synergy begin to make the concept work.  Joanne Younker is Synergy’s president. She’s been working with Dave for 12 years on both the Rise boot and putting together a biomechanical model of how people ski, how joints and muscles and nerves and bones work together to overcome our natural tendency to fall down when the earth starts to slide out from under our feet at an accelerating rate.

Joanne’s a level IV CSIA instructor and a level II CSCF coach and a personal trainer when she’s not on skis.

Sophie Cox and Joanne Younker

She’s been a keen skier since she was fourteen and a student of kinaesthetics since 1989 when she blew her back out squatting improperly in the weight room, an injury leading to temporarily paralysis and a burning desire understand how her body works.

“Working with David, and studying the biomechanics of skiing, I can look at someone skiing and understand what they’re doing wrong and, more importantly, probably why they’re doing it.  That is, what muscles aren’t functioning right or what functions are blocked.  Working with this technology, I can validate my diagnosis with hard data.”

Using a set of dry-land kinaesthetic exercises, Joanne led me through a session designed to help me experience the “feel” of having the right muscles firing and applying pressure with the correct area of my feet.  Once I’d managed to do these correctly, she had me stand on the Pedar’s insoles outside my ski boots.  Connected to the computer, they gave me a real time display of where, in turn, I was applying pressure with each foot. Running me through the exercises again, I could use the display to associate that “feel” with a visual representation of correct pressuring.  There was no guesswork.  When I lit up the right area of the pressure pads, I was having my feet do exactly what they should do to initiate a good turn.

The final step of the exercises was to slip the insoles back into my ski boots and repeat the exercises again.  Within the confines of my boots, I could watch as I pressured the ball of my foot and got my bulk into the right plane of alignment.  I was surprised — as is virtually everyone else who has gone through this exercise — at how far forward I really needed to bring my centre of mass to consistently apply pressure where needed.

All of this might have taken a lot longer to happen if the third member of the Synergy team hadn’t walked into town by accident.  Sophie Cox finished her B.Sc. at the University of Brighton School of Podiatry in, England, in the summer of 1998 and was working in a Podiatry clinic in London.  Her mother brought home a bottle of Whistler spring water  — the same water that gets flushed down toilets in Function Junction, ironically — and she was taken with the idea of goofing off for a year in Whistler.  After some web surfing, she decided to take a job as a bootfitter at Can-Ski and really learn how to ski and party, Whistler style.

A colleague in Boston mentioned the groundbreaking work Dave had been doing in biomechanics and planes of movement associated with skiing to her and she attended a presentation Dave made last March to the Congress of the Canadian Sports Medicine Association.  “After Sophie met David and explained what she’d been doing with the Pedar, he was really excited.  He called me up and said, ‘I’ve met the third person!’ and we went from there,” Joanne explained.

After a summer back in England working , Sophie returned this fall to work with David and Joanne on the biomechanics of skiing and help launch Synergy.  What she brings to the table, in addition to the technology, is an in-depth understanding of the structures and movement of the foot and ankle joints and a wealth of knowledge in diagnosing problems related to feet and lower limbs.

“I look at a skier’s mechanics, what they can and can’t do, and try to decipher why they can’t do it.  Sometimes it’s bad motor skills and that’s Joanne’s part.  But if she’s trying to teach them a skill and they just don’t have the biomechanical capability to do it, that’s where I come in.  I can determine the physiological problem and refer them on to a physio or bootfitter or local podiatrist.”

“The only way of discovering the limits of the possible is to venture a little way past them into the impossible.”  Clarke’s Second Law

For me, the proof of what Synergy was offering was back out on the slopes.  I practiced and visualized what Joanne had shown me, let Sophie make a few modifications to my left footbed and got wired up again a few days later.  Back at the computer after two or three runs, I sat in rapt amazement at the difference.

On the Pedar’s readout, the front of my feet were lighting up at the initiation of each turn.  The tracking line of the centre of force had moved inward — indicating a much stronger pronation, getting the ski on its edge — and my left trace looked like something made by a functioning foot instead of a peg leg.

I know what you’re thinking; almost anyone can help me be a better skier.  That’s like crowing about doubling your money when you only have fifty cents to start with.  But what about good skiers?  What can all this do for them?
Funny you should ask.

In the fall of 1991, during dry-land training in Banff, Rob Boyd blew a disc at the L-5, S-1 joint in his back.  An ensuing laminectomy restricted his mobility and left some nerve damage on his right side— although not enough to keep him off the podium from time to time for the next six years.  “I learned to compensate using different muscle patterns,” he said.

Screen Shot 2017-05-14 at 2.11.09 PM

Three years off the World Cup Circuit now, and away from the daily coaching, Rob wasn’t happy with the way he was skiing this season, nor was he happy with his finishes in the early Ford Pro Series downhill races.  “I saw Jim DeMarco, M.D. wired up to this thing one day and started thinking maybe Dave — who had done a lot of boot work for Rob in the past — could do some testing on me and help me find some answers.”

Sophie and Joanne ran Rob through a gait test, using the pressure pads inside his running shoes while he walked the treadmill at Meadow Park.  “What we saw,” Sophie related, “was Rob had some blockage in the way his foot was functioning.  He wasn’t pushing off the ball of his foot with any force at all but compensating through other muscle patterns.”

Screen Shot 2017-05-14 at 2.10.31 PM

“Right away, from what we saw on the data, my suspicions were confirmed that my right side wasn’t working well,” Rob added.

What they saw when Rob was hooked up to the Pedar for the first time on the slopes was even more surprising.  His heels lit up like a Christmas tree and he was almost never pressuring the front of his boot.  His left turns were strong and crisp but his right turns were nowhere near the same intensity.  “Yeah, that was surprising to see.  It felt like I was skiing alright and using the balls of my feet but I wasn’t even close,” Rob said.

Dave went to work on Rob’s boots, Sophie made some modifications to his footbeds and Joanne got him started on a series of patterning exercises and visualization techniques.  “I could really feel the difference when I started concentrating on using my foot more.  That and the changes in my boot environment made a big difference.  I could feel it right away at Sugarbush (Vermont).  My skis were gliding on the flats; just floating,” Rob said.  He could also see the results in his times: second on his first run and fourth on his second.

 

“The next step will be to set Rob up with a physiotherapy regimen with Allison MacLean,” Joanne said.

And that’s where the remaining synergy of Synergy comes into play.  The company’s goal is to actively work with bootfitters, physiotherapists, chiropractors and other specialists in the community who can treat the whole person.

Allison is just beginning to work with the Synergy people and is excited about the “integrated approach” they’re trying to bring to problem solving.  “The data gathering and testing they’re doing is interesting,” she told me.  “It’s hard sometimes to know exactly what’s not functioning in the case of lower limb injuries and whether what your treatment is as effective as it could be.  When they send someone to me, we’ve got a pre-treatment set of data we can compare to post-treatment performance to really know whether what we’re doing is effective.”

“Every other person you bring into this adds something to the mix and produces even more beneficial results,” Dave explained.  “Sophie and Joanne and I, working together, have a much greater impact than any one of us could have on our own.  That’s the genesis behind Synergy.  But we want to bring the best resources we can to bear and make it so everybody looks like a hero.”

This obviously includes some of the best bootfitters in town.  George McConkey is sold on the idea.  “What Synergy is doing validates a lot of my own ideas about foot function and bootfitting,” he said.  “I still believe 99% of most peoples’ problems are in their boot and with any luck, what we’re starting to see in the way of data coming out of this will get the manufacturers interested in designing boots that work.”

Scott Humby, one of the owners of Fanatyk Co., isn’t so sure what’s going on is going to shake up the industry, but he sees potential benefit.  “I think what they’re doing can help you by really proving what’s going on in your boots.  If it make you feel better about your skiing; you’ll ski better.  If, as bootfitters, we’ve done all we can for someone and they’re still struggling, we’ll definitely send them on to Synergy because there may be something we’re just not seeing.  There’s a huge benefit in being able to refer someone on to a team of specialists.”

It seems axiomatic that what Synergy is doing is the way sports will go in the future.

The advances in sports in the last 25 years have largely come about because of a refinement in coaching techniques and technological innovations in equipment.  But most of what’s being done on the coaching front still relies on what a coach can see and how he or she interprets that visual data.  The advances in coaching and teaching in the next 25 years will probably be realized through the application of measurement technologies only now being brought into the field.

Some people in town and on the mountains think what Dave’s up to is another bit of high-tech quackery, other’s are true believers.  But whether coaches and instructors and others who guide athletes embrace the kinds of tools is probably more a matter of when, not if.  Elite athletes will demand it; the wired generation coming up will assume its presence. And guys like me who just want to get better and shorten the distance between muscle pattern and muscle memory will embrace it the same way we embraced those shapely new skis we can’t live without.

In the meantime, Arthur C. Clarke’s Law of Revolutionary Ideas is probably apropos:

Every revolutionary idea — in science, politics, art or whatever — evokes three stages of reaction. They may be summed up by the three phrases:

1. “It is completely impossible — don’t waste my time.”

2. “It is possible, but it is not worth doing.”

3. “I said it was a good idea all along.”

Watch out for number three.

author- J.D. Maxwell


reprinted with the permission of Whistler Piquenewsmagazine

published on February 18, 2000

FREEMOTION SKI BOOT: PRELIMINARY OBSERVATIONS

Since Simon Zachhuber is a on tight schedule, I am providing my preliminary observations on the FreeMotion ski boot.

A few days ago, Simon sent a copy of what appears to be a patent application for the FreeMotion ski boot. The application appears to have been received by the patent office on September 1, 2010.coverSince I cannot read much German, I would appreciate it if anyone who reads German and who notes errors in my interpretation to please bring them to my attention.

The initial promotional activity for the Freemotion ski boot seems to have occurred between December 28, 2011 and January 25-26, 2012 with videos posted on YouTube. In studying the videos at 0.5 and 0.25 speeds, the skiers demonstrating the FreeMotion ski boot seem to lack fluidity.

In studying the flexion of the Freemotion ski boot, as demonstrated between 0:58 seconds and 1:10 seconds (Perfekte Passform – Perfect Fit) into the video, Freemotion Skischuh Ein & Austieg, it appears that the resistance to forward shank movement is introduced too early and rises too steeply.

Patent Figure 2, below, provides some insights that might explain why the skiers demonstrating the FreeMotion ski boot appear to lack fluidity.

The mechanism that is most likely the primary subject of the patent application is the Flex Spring (annotated in red) that links the shell lower to the rear Exo Cuff. The retention mechanism for the foot appears to be a diagonal band drawn together by cords that exit at the top of the forward aspect of the tongue.

fig-2-annotated

Figure 8, below, shows the draw cords (28, 29) that pull the diagonal bands together. This mechanism draws the heel of the user’s foot into the rear of the lower shell.

fig-8

Summary of my Observations

  • The primary innovation appears to be a U-shaped spring that opposes forward rotation of the Exo Cuff thus transferring force to the front of the shell lower.
  • There does not appear to be any hard limit to the rearward movement of the shank of the skier.
  • There does not appear to be a forward lean (forward angle) adjustment for the exo cuff.
  • There does not appear to be any means to adjust the resistance curve of the spring.
  • If the Heel Retention Mechanism is securely tensioned, it is likely to obstruct the glide path of the distal tibia on the talus. This can cause the center of force on the shank at the buckle secured to the Exo Cuff to rapidly drop down the shank.

As observed in the videos:

  • The resistance to forward movement of the shank provided by the spring mechanism appears to be introduced too early and rises too quickly.

If Simon or others with an interest in the FreeMotion ski boot wish to comment on my preliminary observations, I will respond and try to provide some suggestions for solutions in a follow up post.

NEW AUSTRIAN SKI BOOT: THE FREEMOTION

Yesterday, I found the following comment waiting in que for my review and approval.


Dear David! I am currently working on a project as a student for the FH Salzburg, Austria! We have the task of analyzing a specific ski boot and implementing improvements! Since this is a short project and we are not experts on ski boots, I wanted to ask you for profound feedback on this boot! It can be seen on the website http://www.freemotion.cc

The boot’s concept is that instead of having a hard plastic-shell to deal with the forces, it uses a metal spring that starts at the forefoot and goes through the ankle-axis all the way back over the heel! We already tested it and were quite surprised, how well it worked, but maybe you can add a few thoughts that come to your mind when you check the boot?
I know, it’s very hard to give feedback without having the boot to test, but maybe you can still give some feedback? Thank you very much!!!

With greetings from Austria
Simon Zachhuber


It goes without saying that I offered my assistance to Simon. As Simon said, “it’s very hard to give feedback without having the boot to test”.

While it is hard to assess the FreeMotion boot without being able to examine it and test and evaluate it during ski maneuvers, from what I am able to see in the photos and videos. I believe that the concept holds promise. In important ways, the FreeMotion is remarkably similar to the exoskeleton format of the Rise ski boot that was based on the Birdcage shown below.

birdcage

My vision for a a new ski boot was embodied in the minimalist concept, exo-skeleton Birdcage that I designed in 1991 with biomedical engineer, Alex Sochaniwskyj. MACPOD engaged Alex to consult on the ski boot project. Since the Birdcage was a research vehicle designed to test my hypothesis on the mechanics, biomechanics and physics of skiing and acquire the data needed to design a ski boot based on anatomical principles, aesthetics were not a consideration.

Here is what the Rise ski boot looked like that eventully evolved out of the Birdcage.

image1-2

Here is a design concept sketch of the Rise ski boot.

scan-3

Here is a photo of the FreeMotion ski boot.

freemotion

The red arrow in the photo below shows the rubber wedge at the rear of the shaft of the Rise concept. The wedge was compressed by rotation of the shaft as to arrest forward travel after a specified amount of rotation. The actual Rise boot used a rubber stop in front of the cuff to perform the same function.

concept-w-wedge

The FreeMotion boot uses spring mechanism running along each side of the shell lower body to the back of the hinged shaft. The spring is bent as the cuff rotates forward so as to arrest forward rotation.

Here is the FreeMotion promotional video.

Here is the Rise promotional video.

Here is the promotional material for the Rise ski boot.

1

2

Unfortunately, due to limitations in materials and manufacturing processes that could not be overcome, the Rise ski boot never made it to market.

In my next post, I will review the development process that saw the principles of the Birdcage applied to the Rise ski boot and how the FreeMotion project can benefit from the knowledge gleaned from the Rise project.

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 IMPORTANCE OF STRONG HEALTHY FEET IN SKIING

My work with skiers spanning more than 4 decades, in conjunction with what I have learned over the past three years and papers I have recently read, has led me to the inescapable conclusion that the best equipment available, including ski boots that constrain the foot with minimal interference to foot function, can never overcome the limitations of unhealthy, weak feet.

In working with elite skiers at both the World Cup and recreational levels, it quickly became apparent to me back in the ’70s that these skiers consistently had stronger, tighter feet than lesser skiers. They also had feet whose compact, tight physical characteristics allowed them to attain a good level of function in most ski boots of the day right out the box.

The photos below are of the foot of a female racer who learned to ski at a young age in her mother’s ski boots when her feet were much smaller than her mothers’. The photos were taken when the racer was 20.

wedge-1

When she started racing at 5, she quickly became a phenomenom. She did not outgrow her mother’s boots until she was 11. So the critical period in the development of her feet took place under minimal constraint from her ski boots. Note the ‘natural’ (see footnote 1. below) wedge shape of her foot. There is some evidence of structural damage to her small toe. This could have occured after her she was put in tightly fit (constraining) ski boots at age 12 that were at least one size too small.

wedge-2

Here is the same foot with an outline of a typical boot liner overlaid in red.

liner-outline

Like most, until recently I reasonably assumed that the feet I have today were the feet I was born with; that good skiers were born with good  feet and there was nothing that could be done if one didn’t win the foot lottery at birth. I knew of nothing to indicate otherwise until I started to connect with the rapidly emerging barefoot/minimal shoe camp and the wealth of information on the foot damaging, often debillitating effects, of footwear, especially when one is subjected to foot damaging footwear at an early age. It was only then that I realized that the problems that prevented me from skiing as well as I thought I should didn’t start when I changed from low cut leather boots to the new higher, rigid, all plastic boots. My problems actually started when I was fit with my first pair of ‘orthopedically correct’, stiff-soled, supportive shoes when I was about two. The plastic ski boots only made the damage caused by these shoes, which persists even today, obvious.

An article in the August 9, 2010 edition of the UK newspaper, The Guardian, Why barefoot is best for children contains the following statement.

https://www.theguardian.com/lifeandstyle/2010/aug/09/barefoot-best-for-children

Tracey Byrne, podiatrist specialising in podopaediatrics, believes that wearing shoes at too young an age can hamper a child’s walking and cerebral development. “Toddlers keep their heads up more when they are walking barefoot,” she says. “The feedback they get from the ground means there is less need to look down, which is what puts them off balance and causes them to fall down.” Walking barefoot, she continues, develops the muscles and ligaments of the foot, increases the strength of the foot’s arch, improves proprioception (our awareness of where we are in relation to the space around us) and contributes to good posture.”

When I was fit with my first pair of shoes as an enfant, the big buzz phrase was ‘orthopedically correct’. This implied that orthopedic research had identified a signifcant problem, one that required intervention in the form of supportive shoes in order to ensure that an infants’ feet developed ‘properly’ and that the orthopedic community was behind this initiative. The cover story was that infants feet were weak and incapable of supporting the weight imposed on them in learning to walk. This could cause stress on bones that could lead to permanent deformation of the structures of the feet and legs. Orthopedically correct shoes with stiff soles and sidewalls that supported the foot would ensure proper and ‘normal’ (‘normal’, not ‘natural’ see footnote 1. below) development. This implied that parents who failed to put their infants into orthopedically correct shoes were guilty of child neglect.

Unfortunately for me, my mother had dated a guy in high school who opened a shoe store near our home. He was very much into orthopedically correct shoes. After he sold my mother on the idea she purchased every pair of shoes for me, all orthopedially correct, from his store right up until I was about 5 or 6 years old. The impact on my feet and my childhood was significant.

By the time I entered elementary school, my gait was so impaired that I could not walk in a straight line. Instead, I walked with a distinct, pronounced stagger that was so obvious that my school mates made fun of me. I was clumsy and unsteady on my feet. I fell a lot. My school mates started to refer to me as ‘the gimp’.  (see footnote 1. below)

As hard as I tried, I was never able to make any sports team I tried out for. By the time I reached junior high school, I had given up trying. The interesting paradox was that I could easily outpace all of my friends on a 2 wheeled pedal bicycle. I found out why when I had fitness testing  in 1988. I had a VO2 max of 66 which is phenomenal. So, it wasn’t a lack of stamina or athletic ability that was the issue. It was clearly the damage caused to my feet by the orthopedically correct shoes I was put in as a child.

The Guardian article, Why barefoot is best for children, notes that a study published in 2007 in the podiatry journal, The Foot, suggests that structural and functional changes can result from the foot having to conform to the shape and constriction of a shoe and that the younger the foot, the greater the potential for damage. Since baby feet are structurally different from adult feet, research shows that footwear can, indeed, obstruct proper foot development.

Tracey Byrne: “The human foot at birth is not a miniature version of an adult foot. In fact, it contains no bones at all and consists of a mass of cartilage, which, over a period of years, ossifies to become the 28 bones that exist in the adult human foot. This process is not complete until the late teens, so it is crucial that footwear – when worn – is well chosen.”

In the same article, Mike O’Neill, a consultant podiatrist and spokesperson for the Society of Chiropodists and Podiatrists, said that he believes that too many parents treat their children as fashion accessories and choose shoes on their attractiveness or coolness, rather than their ergonomics. Byrne agrees, but points out that it’s not just parents but manufacturers who have a responsibility. “People see particular shoe styles on sale in the shops – whether it’s a high heel for toddlers, a ‘Crawler’ (a shoe for babies not yet walking) or a cute Havaiana flip flop, with no more than an elastic band at the back … And they think ‘Well, if it’s on the shelf, it must be OK,'” she says.

“As more and more evidence comes to light regarding the importance of going barefoot and the potential dangers of bad footwear, the ‘barefoot model’ will have to become more widely adopted by shoe manufacturers,” says Byrne.

The Bottom Line

“……… the bottom line is the more we use our feet and toes, the stronger they will become. By wearing less of a shoe, we will use our toes to stabilize the foot against the ground and by activating these muscles more often, they become stronger. Simple concept, yet we’ve been missing it for over 40 years by focusing on building the perfect shoe. We already had the perfect shoe, our own foot. We just needed to wake it up and use it. By feeling the ground, our foot can tell the brain which muscles to activate and the foot responds by absorbing shock and working more naturally- the way it was intended to work.  (see footnote 2. below)

“We’ve come to regard the way we dwell permanently in shoes as normal and natural [but it is] anything but,” explained John Woodward, an Alexander Technique teacher who has allegedly been barefoot for 25 years.” ((see footnote 3. below)

All of the preceding applies to ski boots.

In my next post I will explain why going barefoot as much as possible will strengthen the feet but barefoot alone is unlikely to correct the damage done, especially if it was done when feet were developing.


  1. Why Shoes Make “Normal” Gait Impossible: How flaws in footwear affect this complex human function By William A. Rossi, D.P.M. – http://www.unshod.org/pfbc/pfrossi2.htm
  2. STUDY DEMONSTRATES VIBRAM FIVEFINGERS WILL STRENGTHEN THE FOOT. http://www.drnicksrunningblog.com/study-demonstrates-vibram-fivefingers-will-strengthen-the-foot/
  3. Why barefoot is best for children  – https://www.theguardian.com/lifeandstyle/2010/aug/09/barefoot-best-for-children

A READER ASKS ABOUT STATIC PRELOAD AND SR STANCE

I apologize for the delay in taking the static preload issue to the next level; application to stance. There are a number of associated issues that I need to generate graphics and animations for. In the meantime a reader asked the following questions:

“1) Am I understanding “static preload” they way you want us thinking of it? That is “static preload” is the basic optimal stance for skiing.”

COMMENT: The static preload sets up the initial angle of the shank. It provides the foundation on which to build an SR stance. A number of factors, but especially excessive Zeppa-Delta Ramp Angle and arch supports, can prevent the setting up of the static preload. It is important to understand that the static preload is established by a reflex action. It happens as a result of relaxing the hamstrings-gastrocnemius muscles and allowing the weight of the body (CoM) to stretch them.

“This stance would be then modified to accommodate the forces and demands place on the skier’s body by speed, terrain, turn shape etc. In other words, the body once it has learned this optimal stance(s) it will then use the stretch reflex to maintain optimal balance in the Coronal or frontal (for aft) and Sagittal (left right) planes regardless of terrain etc. It is this vital sensitivity element that allows as skier’s brain to actually control the edge/snow interface to effortlessly locomote on skis.”

COMMENT: The stance is configured from the static preload that configures the triceps surae (soleus-gastrocnemius) in isometric contraction. Every day when you start skiing, you need to perform what amounts to a pre ski SR check. I will explain how to do this in a future post.

“2) There is a caveat of course; the boot must be mechanically able to permit the optimal stance(s), or “static preload”. ”

COMMENT: The structures of the boot must enable the 3-dimensional global articulations of the joints of the foot associated with the optimal stance characterized by the posterior chain of muscles (soleus-gastrocnemius-hamstrings) in isometric contraction.

“3) You are suggesting that the “static preload” be a learned experienced in bare feet so that the skier’s neurologic system will recognize the sensation both in skiing and boot fitting. Modern ski boots make both more difficult.”

COMMENTS: Yes and yes. I will explain why soon.

 

DETERMINING OPTIMAL BOOT SHAFT/BOOT BOARD RAMP ANGLE

A follower of skimoves posed the following;

“I’m trying to determine my optimal boot shaft angle and ramp angle given my physiology – i.e. what works best for me. I’ve done some of this work on my own by adjusting binding ramp angle (last season). What is interesting is the shaft angle of my newer Head vs. Lange boots”.


As discussed in recent posts, the importance of the cumulative effect of boot board ramp (zeppa) and binding ramp (delta) angles on stance is becoming increasingly recognized. Although binding ramp angle (delta) typically varies widely from one binding to another in recreational bindings, boot board ramp angle seems to be coming into line with functional reality in race boots. Reliable sources in Europe tell me that the boot boot board ramp angle in World Cup boots is in the order of 2.6 degrees. After I eliminated the arch profile in boot boards for a 23.5 Head race boot, I calculated the ramp angle at 2.35 degrees, a far cry from the 5 degrees claimed for the boot boards. I calculated the boot board ramp angle of an Atomic race boot of a local ski pro at a little over 2 degrees. I have also been told that shim kits are available for all race bindings that allow the delta angle to be zeroed.

The default barefoot ramp angle for humans is zero. It has been unequivocally established that anything more than a small amount of ‘drop’ (heel higher than forefoot) in footwear will have a detrimental effect on stance, balance and movement patterns. This especially true for balance on one foot, something that is fundamental to sound ski technique.

Elevating the heel relative to the forefoot will cause the muscles in the back of the lower leg to contract. Over time, these muscles will become chronically shortened. The key muscles affected are the calf muscles; the gastrocnemius and soleus. But the small muscles that stabilize the knee and pelvis are also adversely affected, not a good thing.

If I want to find the optimal boot shaft angle and compare the shaft angle of two or more boots, I start by making the boot boards perfectly flat with the transverse aspect horizontal with the base of the ski. I set the boot board ramp angles for both boots at 2.5 or 2.6 degrees. Since it can take a long time for the body to adapt to even small changes in ramp angle underfoot, the angle is not hypercritical.   I have settled on 2.5 to 2.6 degrees of total ramp (zeppa + delta) as an arbitrary starting point. Although there appears to be a positive effect of a small delta binding angle in SL and GS, I prefer to work with a zero delta angle initially since a positive or negative delta affects the shaft angle of a ski boot.

When moving from one boot model to a different model or to another boot brand, the first thing I do is remove the boot boards and calculate the ramp angles with the top surface monplanar. If the boot boards are not flat, I plane or grind them flat. If a new boot is to be be compared to a current boot with a boot board angle of 2.5 to 2.6 degrees, I modify the boot board of the new boot so it has the same angle as the current boot.

Next, I compare the shells and the angles of the spine at the back of the shaft of each boot. Even if the angles of the spines of the boot shells appear similar, there is no guarantee that what I call the static preload shank angle (more on this in a future post) will be the same.

A quick check of how the structure of the shell of the new boot is affecting the functional configuration of the foot and leg compared to the current boot, is to put the current boot on one foot then put the new boot shell with the liner from the current boot on the other foot. If a significant difference is perceived, the source is the new shell.

At this point, it may be apparent that there is a difference in the shank angles of the left and right legs when comparing the current boot to the new boot. But whether one boot is better than the other or even if one boot eanables the optimal static preload shank angle would not be known. I will explain how I identify this angle in my next post. For now, study this recent video of Lindsey Vonn starting off by skiing in what appears to be a strange ski stance. In fact, the exercise Vonn is doing is a familiar routine to me, one that I do before I start skiing – https://www.facebook.com/LindseyVonnUSA/videos/10154672700589728/

Why is Vonn skiing this way? What is she trying to do?

Also, check out this screen shot of Anna Fenninger. Note her compact, forward in the hips stance.

fenninger-1

Finally, watch this video in which Brandon Dyksterhouse compares Shiffrin and Fenninger – Shiffrin GS Analysis – https://youtu.be/phchHWwDhdY

What do Vonn and Fenninger have in common? Why?