SHOE/LINER HACKS


There is no point in continuing my discussion of the mechanics of balance on the outside ski because the odds are great that ski boots are preventing most skiers from engaging the mechanics required to apply the torsional forces to a ski with which to establish a balance platform under the outside foot.

In the scheme of things, an essential first step is to adapt the ski boots to functional needs of the skier as opposed to forcing the skier to adapt to the limitations imposed on them by the ski boots. Tightly fitting, supportive ski boots and most conventional constricting, cushioned, supportive footwear actually makes the feet weaker while compromising postural alignment and balance. There is an emerging global movement that is recognizing conventional footwear as THE problem behind compromised foot function while creating a ‘perceived need’ for cushioned soles  and artificial support in the form of custom insoles and orthotics which, instead of solving functional issues in the feet, lower limbs and entire body, further weaken the biokinetic chain.

The links below are to 3 articles that speak to this subject.

ORTHOTICS OR NOT => OUR LIMITING FOOT BELIEFS ARE HURTING US – http://kristinmarvinfitness.com/orthotics-or-not-our-limiting-foot-beliefs-are-hurting-us/

YOU WERE BORN WITH PERFECT FEET – https://www.correcttoes.com/foot-help/feet-101/

STRENGTHENING VS. SUPPORTING: THE COMPETING LOGIC OF FOOT HEALTH – https://www.correcttoes.com/foot-help/strengthening-vs-supporting-competing-logic-foot-health/

There is currently a whole series of Foot-Cast Episodes on The Foot Collective site at – http://www.thefootcollective.com

see – THE HUMAN GUIDEBOOK FOR SWITCHING TO BAREFOOT FOOTWEAR


A good starting point is to acquire a sense of how day-to-day footwear compromises foot and lower limb function and the modifications or ‘hacks’  necessary to adapt the footwear to the functional needs of the user.

A recent post on the Correct Toes blog called ‘How to Modify Your Shoes to Better Fit Your Feet’ (1.), comments on a runner who was experiencing distracting numbness and tingling in her feet, but balked at allowing her coach to make a few cuts in the upper material of her shoes to relieve the tension that was causing her problem. Most people are uneasy with the idea of modifying footwear. They tend to readily accept standard, off the shelf shoe size fit and assume that the way a shoe fits (or doesn’t) fit their foot is the way it is supposed to fit.

I recently had a similar experience with a young ski racer whose toes were crunched up in her ski boots that were both too short and too narrow. The liners were especially bad. Like many of today’s young racers, early in her racing career, she had probably grown accustomed to the constraint imposed on her feet by her ski boots and had unconsciously learned to make her feet comfortable by standing with most of her weight on her heels. After a time, her body had come to accept this as ‘normal’. Once this happened, she became reluctant to make changes.

A ex-racer, who I worked with back in the 1970s, loaned the young racer a pair of her boots. The improvement in the racer’s skiing was immediate and remarkable. Her coach commented that she had made 6 months improvement in one day! Unfortunately, stories of skiers and racers whose foot function, balance and even the function of their entire body has been compromised by tightly fitting, supportive ski boots is common. But happy outcomes, such as this young racer experienced, are exceedingly rare.

The Correct Toes post offers some good suggestions on footwear modifications that are remarkably similar to those I have used for decades in both ski boot liners and in my own footwear. The reason the modifications are similar is that the end objective; creating a functional environment for the user by minimizing the negative impact of the footwear on foot function, is the same.

The series of photos that follow illustrate examples of modifications that can improve the functional fit of footwear. An easy modification is to reconfigure the lacing pattern. Just because a shoe has a specific set of lace eyelets does not mean they all are necessary. The 2 photos below are from the Correct Toes article.

Photo with permission of Correct Toes

The photos below are the lace hacks I made on my Xero Prio (left) and Lems Primal 2 (R).

One modification that the Correct Toes article does not mention is the use of lace locks. Lace locks allow lace tension to be regulated and maintained without the need to over tighten laces to prevent them from coming undone.

This is one form of lace locks on my Xero Prio.

This is another form of lace locks on my Lems Primal 2.

I also use Correct Toes to improve foot function.

Correct Toes, The Foot Collective, EBFA, Feet Freex, EM Sports and many others are advancing on a uniform front in lock-step with the makers of minimal shoes in recognizing the damage caused to feet by conventional footwear while moving towards a uniform standard for the design and construction of footwear that creates a functional environment for the foot, while minimizing the negative impacts associated with structures placed on the human foot. Technologies such as NABOSO hold the promise of advancing on barefoot function in what I like to call ‘Beyond Barefoot’.

It has long been my experience that liners are the most problematic aspect of most ski boots. When I worked exclusively with Langes, I often made extensive modifications to liners that included using a liner a size larger than the shell size and re-sectioning and/or re-sewing the forefoot to allow proper alignment of the big toe and adequate width for the forefoot to fully splay.

The biggest problem in ski boot liners is in the toe box, especially the shape of the toe end in that it forces the big toe inwards, towards the center of the foot.

A modification that the Correct Toes article suggests is to make small slits on the side of the footwear opposite the point where the foot needs more room to splay.

Photo with permission of Correct Toes

Cutting small slits along the base of a ski boot liner is the first hack I usually try. But in many cases, I find more drastic modifactions are necessary in order to obtain the width required for the foot to fully splay and the big toe to align properly.

The photos below are before (L) and after (R) modifications that were necessary to accommodate my wife’s feet. These are older race stock Lange liners which I fit to her extensively modified Head boot shells.

The photo below is of the modified liner from my Head World Cup boot.

For ‘shallow’ feet or feet with a low instep the Correct Toes article suggests adding tongue depressors along the top of the foot or under the laces to help fill the void and prevent the foot from lifting or sliding around.Photo with permission of Correct Toes

The photo is of forefoot/instep retention pad that applies a constraining load to the foot that is substantially perpendicular to the transverse plane of the boot board. This device is similar to the one that powered Steve Podborksi to the podium in World Cup Downhill races. Today, Steve remains the only non-European to have ever won the World Cup Downhill title.

I devoted a large portion of my US Patent 5,265,350 to laying the groundwork for a functional standard that could evolve and eventually be applied to all forms of footwear, but especially ski boots. There are encouraging signs that the ski industry has finally started to take baby steps in this direction. I will discuss this in my next post.


  1. https://www.correcttoes.com/foot-help/modify-shoes-better-fit-feet/ 

8 comments

  1. All;
    Since I spent many years of my life not being able to run and also limited time to hike etc.; it may sound stupid but I never saw a connection of ‘cross training’ between walking and skiing or anything other than roller blading to skiing. I usually work backwards compared to the normal person, so now I’m taking what I learned about ski boots and applying it to regular footwear. Now I can see the ‘cross’ connection between walking/running/ hiking and skiing very clearly. So I’m fiddling with my footwear (which in some ways is harder than ski boots) because in most of those one can pull out the foot board and mess with it but can’t really do that with regular foot wear. The past couple of summers working with what David presented on regular footwear enabled me to work on things that truly apply to skiing and ski boots when not on snow. This summer’s topic (carried over from sometime last year) on pressing the big toe is going to be a huge advancement come skiing time.

    David introduced me to some new concepts I had just started scraping the surface on; toe spread, ankle glide path, being major items. So gratefully I didn’t have to figure those things out completely on my own so I’ve had a much faster learning curve in spite of not being to a seminar with David, on them compared to some items I worked on myself for years. Those two items have so improved my stance and gait in my regular footwear that the last few years I’ve been able to run, sort of, and hike a lot more so I’m playing continually with my stance and placement of my feet especially when off the tarmac. Even if there’s still a bit to go before a 100% healthy knee, at least I can do all this without injuring it which avoids set backs. By walking with forefoot strike, the tension in my legs allows me to ‘recover’ easily from hidden things. Just yesterday I stepped onto the first step of an outdoor stairs that has shifted to an odd angle over time. My foot did a weird twist but the tension limited the displacement so it didn’t effect my knee or anything else. Contrast that to last year, I was mowing the lawn, stepped heel down first, unfortunately in a hole and twisted my good knee It fortunately was fine very quickly but I’m grateful it wasn’t the other one. After decades of impeding footwear it’s taken me a few years to feel comfortable with the fore foot strike and begin to feel natural with it. Problem was that I hadn’t modified my rubber boots enough until last year because the difficulty involved, so switching back and forth between what works well and what I’m stuck with off-the-shelf really screwed up the change over in walking pattern. Logically that tells me then if one gets this ingrained in everyday activity it will come quicker in the ski boots so get all your footwear up to snuff and practice walking correctly:).

    As far as getting the work done on the ski boots; do it yourself. Go to a swap, second hand store, ebay, and buy a pair of boots cheap and don’t hesitate to go up one full size. I think for non-competition skiers it may be easier than having to trust a boot fitter you can’t trust with expanding the boot shell. I finally went up one size myself this past season with a real low end pair of boots and liked it so much I haven’t even looked for a ‘better’ boot. If you are working closely with an expert, go with the snugger fit. Only one comes to mind I personally would trust (it’s not me so there’s only one other choice on the planet:) Make it easy on yourself for starters and go a bit looser. You can always go back to your original boots if things don’t work out. Just from reading the advice David has put on this site, looking at the patent information, and the ‘Bird Cage’ will give you plenty to work with and if you start with an open mind you’re already light years ahead of most boot fitters:) I can almost guarantee you’ll be skiing better than any time in your life right away. I didn’t get everything right from the Manifesto on all the first tries. A few I asked the source who helped me sort out where I goofed up but find that my biggest problem is that I still err on the side of caution and don’t do ENOUGH of a given change the first time. You’ll also soon enough figure out that most footwear, ski boots included, are so far from being what you need on your feet that it’s really hard to make things worse than they already are:)

    1. Thanks Michael. I agree completely with what you said about most footwear, ski boots included, being so far from what you need on your feet that it’s really hard to make things worse than they already are; things can only get better! Recently, I have seen signs that even the ski boot makers appear to be turning the corner. More on this soon. David

  2. Dear David
    I would echo Thomas’s opening comments.
    I have found your insights very helpful to my own skiing though my boot modifications have been limited. Expanding my toe box and using a zip fit liner to enjoy their soft neoprene toe box and not using the lacing system and not over tightening the boots / abusing the powerstrap, and of course removing the arch support from my foot beds.
    The mechanical considerations have made a hugh difference . I spent a long time asking how it was possible to put so much effort into getting a high edge angle without any success. I now know and more importantly can get those edges gripping. I am not a racer but I do teach occaisionally and have tried to add these skills to my teaching. Having an understanding of why they work seems really important in legitimising this.
    Unfortunately we can not wait for the perfect boot set up but have to do the best with what we and our students have.
    Thanks for your insights-

    1. Hi Mike,

      Comments from those such as yourself and Thomas are both helpful and encouraging to my efforts. Assuming a skier or racer is able to create a functional environment in their ski boots to support the biomechanics and mechanics of the heel to forefoot diagonal impulse rocker mechanics and torsionally stiffen the ankle and knee joints, it becomes natural and intuitive step to apply the whole leg rotation into the turn that creates a platform to stand and balance on. Liners are THE problem that must be overcome. I am finally seeing movement by boot makers on this issue.

      I will try and take the outside ski balance mechanics to a conclusion as soon as possible. Input from yourself and Thomas will help guide my efforts

      1. Dear Mike,

        I was intrigued by your observations, “I spent a long time asking how it was possible to put so much effort into getting a high edge angle without any success. I now know and more importantly can get those edges gripping.”

        As I read these lines the way I am hearing them is the base of support is the medal side of the hard secure longitudinal arch of the outside ski foot. I say outside ski (big toe vs. little toe edge) because it seems more difficult to establish a stable ski- foot-shank-upper body chained and balanced wait baring connection thusly. It is actually damn hard to do this. Dave has suggested using lateral pressure on the medial boot top or friction of pushing the shin into the boot tongue as a boot-foot mechanism. If I am not mistaken he goes on to suggest this does not develop the body mechanics needed to produce a griping ski edge.

        Unless the skier understands how to create a hard arch (Vladimir Janda ET all) and has foot bed/boot that allows it all is for naught. I think Dave says it this way “Body mechanics first, then onto ski mechanics.” That sort of lays out a conjecture about a gripping edge but how are you Mike experiencing it?

        Mike and Micheal thanks for the congenial exploration.

        This blog is a living explanation of the development and evolution of skiing body mechanics. It is rather too bad that derogatory things have been written about this dialogue. If those ill tempered people were to engage in a meaningful way here actually sharing there expertise, general knowledge and understanding of the sport could advance faster within a congenial community of enthusiasts. thomas

      2. Yours and other comments help me to understand where the voids are that need filling in. The key event in a sequence of ski turns is edge change. For some reason, this is absent from discussions on ski mechanics. The only person I am aware of who raised this aspect is Lito-Tejada Flores who emphasized the need to move to the inside ski in a transition phase.

        “Unless the skier understands how to create a hard arch (Vladimir Janda ET all) and has foot bed/boot that allows it all is for naught. I think Dave says it this way “Body mechanics first, then onto ski mechanics.” That sort of lays out a conjecture about a gripping edge but how are you Mike experiencing it?”

        It is more imvolved than a hard arch. It is knowing how to create the high loads associated with late stance and commitment to propulsion at ski flat that occurs between edge change without commiting to propulsion. I discounted late stance back in the 1970s because it was obvious that there is no propulsion in skiing and by elimination concluded skiing is a mid stance activity as many today continue to allude to. But I later realized this was a serious error. I will write a post that explains the mechanics and biomechanics of the impulse load/platform stance. This description does exist anywhere in the literature. So is not known and far from obvious. As far as I know, it is original thinking. If the followers of my blog can understand this aspect, everything else should become obvious

  3. Dear Dave,

    It is rather sad to think of you discontinuing the dialogue here about mechanics of balance on the outside ski as it has been most thought provoking.

    Actually the digression into foot mechanics is gives a great deal of support to the ideas being expressed on these pages about the body mechanics that should optimally govern the relationship between outside and insides ski starting before transition and continuing through transition and into the full turn.

    With respect to the 1970s ski racer who skill was advanced 6-months of training overnight by better boot fitting one has to assume that a week of valid foot movement instruction could have recalibrated the brain to replace several years of race coaching. Half of the glass maybe footwear but I would wager at least 50% is training to use one’s feet in ski boots.

    I enjoy the development of ideas here. I find pleasure in all the different avenues of inquiry while being impatient that the answers to questions often raise more intrigue and questions.

    Hoping the heat of summer will change to snow falling and renewed interest in dynamics of switching balance between skies, thomas

    1. Hi Thomas,

      I have not had a lot of time to devote to my blog the past few months. The saying, “So much to do, so little time to do it” comes to mind.

      It was a racer I worked with in the 1970s who loaned a pair of boots to the young racer who her coach commented made 6 months of improvement in one day.

      It is all about body mechanics and especially how body mechanics and the balance processes are affected by ski boots. My strategy, dating back to the mid 1970s, was to observe and analyze skiers and racers with the objective of understanding what was affecting their movement on skis. If, for example, a racer was throwing one or both of their arms up during a turn, instead of telling them, “Don’t throw your arms up” I asked myself, “why are they doing that”. Throwing the arms up is a spinal reflex stage 3 alarm balance survival strategy that usually indicates a problem at the foot ground (snow) interface.

      The reason I decided to delay attempting to take the mechanics of balance on the outside ski to a conclusion is that the past 2 years have taught me how badly bad ski boots can disturb the normally effective movement patterns of even a gifted athlete. I usually start my process by asking skiers or racers who would like to work with me to send me video of them skiing. I usually get this well before we meet in person. When I analyze the video, I usually see gifted athletes trying to make effective movements but can’t. These are natural skiers whose bodies know what to do. But it can’t no matter how hard it tries. I simply have to remove the impediments and create a functional environment in their boots. I release the hounds and stand back and watch the skier fly. Fixing ski boots can be harder than it sounds for a number of reasons. Liners are the biggest issue by far.

      The key issue in setting up balance on the outside foot/ski is the roll over that occurs at edge change and whether a biomechanical rocker action translation occurs. Edge change and roll over is not even on the radar screens of most discussions of ski technique. So skiers and even racers tend to gloss over it because no one has ever said it was an issue, let alone important. The mechanics of the application of torque by the rotator muscles of the hip and leg is a serious subject in itself. It is far more complex than most could imagine.

      Body mechanics first, then onto ski mechanics.

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