WHAT DOES HIRSCHER HAVE IN COMMON WITH BRIGNONE, WORLEY AND SHIFFRIN?


The short answer to this question is that the 4 racers share a stance with the muscles of the biokinetic chain in isometric contraction during what I term the Load Phase of a turn sequence and the ability to use the elastic recoil energy created during the Load Phase for acceleration.

One of the key visual cues of an isometric stance is an extended outside leg with small angles at the knee and ankle and a forward position of the pelvis. Another key visual cue is high hands with arms reaching forward as if the racer is trying to reach forward and hug a large barrel.

The screen shot below is of Marcel Hirscher in the December 16, 2018 Alta Bada GS that he won by 2.53 seconds.

The screen shot below is of Tessa Worley in the 2018-19 Soelden GS.

Reductionist Anatomy

A longer answer to the question posed by the title of this post, one that I will expand on in future posts, is that Hirscher, Brignone, Worely and Shiffrin are examples of the application of the principles of an emerging paradigm that is challenging the fundamental way in which muscular anatomy has long perceived muscles as separate systems with specific functions. In the new paradigm that has arisen out of recent discoveries muscles function in conjunction with the myofascial network as a wholly integrated system; one that responds and adapts to the stresses imposed on it. Since these discoveries are almost ten years old the odds are that the dominant technique of Hirscher, Brignone, Worely and Shiffrin is not by chance.

In previous posts, I described a stance based on isometric contraction as the SR Stance. SR is an abbreviation for the Stretch Reflex. Technically, a better term for the stretch reflex is the stretch-shorten cycle

The reason I chose SR for the name of the stance is that isometric contraction and the stretch reflex are not part of the narrative of ski technique. I discuss the three forms of muscle contraction in my post I-C-E: SR (2.) which I have recently updated.

The reason a ski stance based on isometric contraction provides a huge competitive advantage has to do with recent finding discussed in a 2009 article (1.) in which ultrasound imaging that allowed for quantitative assessment of the mechanisms for elastic energy storage and return at the ankle joint during human walking found that the Achilles tendon stores elastic energy as the mid stance phase progresses until the energy peaks in late midstance and is released to produce a rapid recoil with very high peak power output. The researchers named this the Catapult Mechanism (3.).

An important feature of the ankle ‘catapult mechanism’ is that the stretch and recoil of the Achilles tendon allows muscle fibers to remain nearly isometric producing high forces with very little mechanical work. In the isometric state, muscles expend much less metabolic energy to produce force when compared to muscles shortening in concentric (positive work) contractions.

Recent research has also found that during explosive movements, the contractile elements of a muscle remain in an isometric state to increase tension in the non-contractile components in an effort to produce higher levels of force. The enhanced stiffness from the contractile component can help the connective tissue rapidly store mechanical energy during the lengthening (recoil) phase delivering greater power output during the shortening phase. (4.), (5.)

What all this means is that the power advantage seen in racers like Hirscher, Brignone, Worely and Shiffrin results from an integrated system. But the human body can only function as an integrated system under conditions which allow multi-plane movement, something conventional ski boots intentionally interfere with.

In my next post I will start from what I see as the fundamental element of a ski stance based on isometric contraction and progress upward from there.


  1. It Pays to Have a Spring in Your Step – 2009 Gregory S. Sawicki1, Cara L. Lewis2, and Daniel P. Ferris2 – 1. Department of Ecology and Evolutionary Biology, Brown University, Providence, RI; and 2. School of Kinesiology, University of Michigan, Ann Arbor, MI
  2. https://wp.me/p3vZhu-1wT
  3. Fascial Fitness: Fascia oriented training for bodywork and movement therapies – Divo G. Muller, Robert Schleip 
  4. Cutting Edge: Training the Fascial Network (Part 1) by Pete McCall M.S.
  5. Cutting Edge: Training the Fascial Network (Part 2) by Pete McCall M.S.

 

7 comments

  1. Hi David,

    As a skier with long legs (fermur and tibia) I have struggled for years to “get forward,” ” get out of the backseat”, etc. and simultaneously “keep the cuff tight”, with helpful suggestions like “just lean forward”, “crush the tongue”, etc. The taller you are the more difficult it is to get over the “sweet spot” on the ski especially if the boot is upright, stiff, and without forward lean or flex adjustability. When I asked my ex-bootfitter how guys like Bryce Bennet and Matt Zennhausern (both about 6’7″) can ski so well, he said “They can stand on their skis”.?? That mentality is very demoralizing, yet incredibly pervasive in the ski world and often comes from people who have the small percentage of perfect anatomy for skiing. I was recently in a shop chatting with a PSIA Examiner about the Skier’s Manifesto and cuff flex and he didn’t understand what I was talking about when I mentioned how helpful it was to ski with about 12 degrees of free flex in the cuff with fore and aft limits. He said he keeps his cuff tight and has does not use the tongue and does not notice it even in bumps. I concluded that he must be one of the chosen few, of course he was being fitted in plug boots. So, this is a guy who teaches and evaluates ski instructors! ?? Meanwhile right in front of us the shop owner/bootfitter was telling a young racer “I want you to crush the tongue of the boot when skiing”. I believe the owner is another of the chosen few as well. He once told me he couldn’t understand people who tell him the front of their foot comes up off the bottom of the boot when they lean forward. “how can you lean forward and not be pressing on the bottom of the boot?” He had no response when I told him I know that feeling, I’ve been there, trying to get forward but being blocked by the cuff and pulling up on the front of the foot while leaning forward. I also told him something is impeding the ability to press on the ball of the foot, probably the cuff. Of course, neither of these guys thinks ramp angle has any effect on skiing ability either.

    It seems the ski industry is commiting suicide by listening to those few and not the masses of dedicated enthusiastic skiers such as myself and of course people like you David, who are labeled as “nerds” or “too scientific”, etc. while doing the hard work the industry is afraid of yet, which could make skiing much more accessible to many more people. It will require real courage and open mindedness, both in short supply in the ski industry.

    A quick comment on your blog The Truth About Power Straps”. I was unable to find any description of the rearmost position of the leg in the cuff and the limit of rearward movement of the leg. I did not find that until the blog “Stance Muscle tensioning Sequence Exercise” was issued. I will try to review my printouts of your blogs and pass on other questions and ideas to aid your reboot efforts.

    Thank you for the amazing and definitive work as always,David.

    Regards,
    Herb

    1. Hi Herb,

      I can relate and empathize with you. I had no idea how easy it would be to become smug about my skiing ability until I created a functional environemt for my feet and legs in my ski boots. Suddenly, the whole world changed and I could ski as easily as I walk. The only thing I think about now is where I want to go. Everything else just happens automatically at a subconscious level. I also have no sensation of anything on my feet except for the pressures under the soles of my feet which quickly fade into the subconscious after a few turns. As I ski past other skiers using about 10% of the energy and effort they are using and with superior control it’s hard not to feel smug even though I detest it.

      “They can stand on their skis” Seriously? This is elitist arrogance that is in no way helpful. It is the exact opposite; mocking and degrading.

      I agree with your comment about the ski industry committing suicide. But they are committing suicide on behalf of the sport and the skiers. In order to maintain ignorance as the status quo and deflect criticism those who try to bring science to skiing to make it safer, easier and more enjoyable and grow the sport are labelled as nerds who make skiing too complicated. Read the article on ‘Automaticity in Sport’ in the followng link – http://psychology.iresearchnet.com/sports-psychology/perception-in-sport/automaticity-in-sport/ and it should become patently obvious that it is the ski industry and especially the design and construction of ski boots that is making skiing unnecessarily difficult.

      I will edit my comment later to add material on the rearmost limit of the leg in the cuff. For now, please walk slowly barefoot on a hard level floor and you should sense the foreward most and rearward most limits of the movement of your leg as the mid stance phase of the support leg progresses forward to terminal stance as defined by heel separation from ground. Pay close attention to the straightening of the ankle that occurs in conjunction with knee extension towards the end of mid stance. I will explain the implications later.

      Have faith. Help is on the way.

      Best regards.
      David

      January 12, 2019

      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

      .

      – Sports Medical Criteria of the Alpine Ski Boot – W Hauser
      P. Schaff, Technical Surveillance Association, Munich, West Germany 1987

      Sound familiar Herb?

      Here’s what international authorities on biomechanics said in 1987 about what a boot should be:

      From a technical (skiing) point of view, the ski boot must represent an interface between the human body and the ski. This implies first of all an exchange of steering function, i.e., the skier must be able to steer as well as possible, but must also have a direct (neural) feedback from the ski and from the ground (snow). In this way, the skier can adapt to the requirements of the skiing surface and snow conditions. These conditions can be met if the height, stiffness, angle and functions (rotational axes, ankle joint (AJ)/shaft) of the shaft are adapted, as well as possible to the individual skier.

      Biomechanical Considerations of the Ski Boot (Alpine)
      Dr. E. Stussi, Member of GOTS – Chief of Biomechanical Laboratory ETH, Zurich, Switzerland

      ETH Zurich is one of the top biomechanical Laboratories in the world

      1. Hi David,

        Thank you for the encouragement, David. My faith in you and your work is undiminished. Faith in the industry , not so much. I ran across an article about a mountain guide in an old Outside Magazine who commented that just because indigenous people have been doing things the same way for thousands of years does not make it the right way! Yes, the battle against intentional ignorance must go on for the sake of progress.

        Lately I have been noticing that after 30 years or more of wearing orthotics in footwear and ski boots and several years of being ” barefoot” that my “normal” walking patterns as you have described in various posts, has been compromised somewhat and I do have to be attentive in a skill acquisition mode particularly when walking on uneven ground. I have found that a slightly lowered stance helps to absorb terrain but, a taller more upright stance feels much stronger and natural. It seems that I need to focus on what should be an “automatic” supination to pronation sequence with more attention. When I do, the knees and legs feel stronger and more able to deal with the terrain. Apparently the orthotics have compromised my movement patterns as well as interfering with natural foot function. It is as if there is a reticence to pronate left over from the orthotic use and the constant mantra that pronation is bad, a human weakness, etc. and that it has interfered with the supination phase as well.

        Thank you for the suggestions.

        Best regards,
        Herb

  2. Re Federica Brignone: Pure Pelvic Power:

    She starts with ankle and knee flex in which the pelvis [in the strong position of pelvic tilt] is stacked over COM. As the ski enters the power apex of the turn, extension of the ankle-knee of the outside ski to the ‘catapult ready’ moment, results in forward movement of the pelvis since the femur is longer than the tibia. The catapult effect of the SR reflex is exerted at a COM position slightly more forward than the average skier providing better COM angle to the running surface of the ski; resulting in more force balanced along the ski length and greater explosive acceleration.
    We use the same concept in very shortline slalom water skiing.
    The skier with COM slightly further back ends up with more tail than tip contact/pressure with possible energy loss via tail skid as a result of the unequal pressures and less ability to establish cross course angle without skid..

    Bob Drake

    1. Thank you for the interesting comments. I’m not sure what you mean by “She starts with ankle and knee flex in which the pelvis [in the strong position of pelvic tilt] is stacked over COM”. The most reliable marker of COM is the position of the pelvis in relation to the feet. In the case of skiers like Brignone COM is behind their feet in the transition or float phase of a turn sequence. The studies cited in my last post explain how the movement sequence preceeding the loading/catapult phase is a pre-activation phase. I didn’t realize that water skiers use similar mechanics in shortline slalom. But it makes perfect sense.

      1. You are quite correct. With knee bend and ankle bend, and the tibial length being less than the femur length, the pelvis will be posterior to the feet: and, as you have pointed out, the COM will be posterior to the feet. Am I incorrect in deducing that the value of the straightening of the leg is twofold: achieving the ‘Catapult ready’ position [SR engaged], and moving the COM anteriorly over the feet? and that the timing of this change is equally critical?
        I am an enthusiastic amateur snow skier and enjoy your approach to the physics of skiing very much. A lot of what you say is very germaine to high end water skiing, and very few in that sport approach it scientifically.I am rather lonely in this interest. Water skiing is 20-30 years behind snow skiing in binder design, safety, and scientific bases for technical application, much like where snow skiing was when you started to enlighten folks in the 60’s and 70’s. I would very much like to send you some crossover [snow/water] thoughts to stimulate your grey cells a little outside of the box, if it is convenient for you at some time in the future. I am reluctant to post them on a snow ski blog where I presume most of your readers would find them of no interest.
        If you have an inkling to play with this a bit in your free time, I would be delighted. Left me know where I should download some info if you are .I understand this is a busy snow ski time and may not be the time for this pursuit and leave this with you as simply a challenge for a rainy day…

        Regards

        Bob Drake

      2. Am I incorrect in deducing that the value of the straightening of the leg is twofold: achieving the ‘Catapult ready’ position [SR engaged],
        > Yes
        and moving the COM anteriorly over the feet? and that the timing of this change is equally critical?
        > Yes. The movement sequence and timing of events is critical.

        I am an enthusiastic amateur snow skier and enjoy your approach to the physics of skiing very much. A lot of what you say is very germaine to high end water skiing, and very few in that sport approach it scientifically.
        > Very few in skiing approach the issues scientifically. Instead, the industry has created what amounts to a marketing narrative based on techy terms that imply knowledge and support in science. As is now being widely embraced the human body functions as an integrated system not a bunch of disparate bits and pieces. I coined the term Bio-Integration decades ago. It is also now being widely recognized that walking is the default movement pattern with contra lateral movement; when the right leg is the stance leg and the left leg is the swing leg the left side of the pelvis advances with the swing of the leg and vice versa with internal rotation of the stance leg and external rotation of the swing leg in a bio-integrated action. What does the ski industry do? They call this steering and separation, the exact opposite of what is really happening.

        I am rather lonely in this interest.
        > This is the story of my life. We are in an exclusive club.

        I would very much like to send you some crossover [snow/water] thoughts to stimulate your grey cells a little outside of the box,
        > Box? There is no box in my world.
        if it is convenient for you at some time in the future. I am reluctant to post them on a snow ski blog where I presume most of your readers would find them of no interest.
        > I’m always interested in new challenges. Einstein nailed it when he said, To raise new questions, new possibilities, to regard old problems from a new angle, requires creative imagination and marks real advance in science. The summer is a better time for me to think about water skiing. Just post a comment and label it as a message so I won’t publish it. In the meantime, If you have any snow ski issues you want to raise please do so. Feedback helps guide may efforts.

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