LIGETY’S KEY MOVE


In the last week the traffic on my blog has exploded. Thank your for your interest. The top viewed post yesterday and today by a long shot is SORRY TED, YOUR TECHNIQUE ISN’T NEW. It is not so much that Ted’s technique is not new but more  a case of Ligety taking what I call the skimove to a higher level enabled by the new GS ski geometries and construction.

As I point out in my post, it was about 1985 that I started to notice that elite skiers seemed to be moving differently than lesser skiers. I think the reason few noticed is that ski pros and coaches tend to rely primarily on the skills of observation to analyze what the best skiers are doing. If the knee turns into the turn, it is assumed that the skier is consciously turning the knee into the turn (actually, the whole leg is turning). Hence the oft heard advice to, “drive the knees into the turn”. When I pointed out to others that skiers like Erika Hess were moving onto their inside ski in what seemed like an early move I was told that they were just finishing their turn on her inside ski. But it seemed to me that something more was going on.

Eventually, I came up with a hypothesis (theory) that posited that elite skiers were somehow engaging the external forces to drive their outside ski into the turn. I wasn’t sure exactly how they were doing this. So in 1991 MACPOD, a company I was a partner in, engaged scientists to help figure out how we could test my hypothesis during actual ski maneuvers on real ski slopes. This was done with a laboratory device that replaced the ski boot. Key aspects of the foot and leg were instrumented so a sequence of force patterns associated with the series of events required to engage the external forces could be captured and analyzed. As part of the study, joint actions associated with pronation, were blocked. The studies confirmed what I had suspected. If a skiers’ outside foot was prevented from pronating, the skier cannot engage the external forces.

In a series of posts on THE MOMENT OF TRUTH I explain how Ligety’s CoM rotates about the inside edge of the inside ski as he moves onto it until the ski is flat on the snow. What I have yet to describe is the movement that Ligety makes when the ski flattens on the snow that moves the centre of force (centre of pressure) under his new outside foot to the ball of the foot. As Ligety’s CoM moves forward, his leg develops an angular relationship with his foot as Centre of Pressure moves forward from the centre of his heel on an arc to the ball of his foot. This happens as the ski is changing edges and rotating into the new turn. You can see this angular relationship of the leg with the foot if you look carefully in my posts on Mikaela Shiffrin. Figure 23B (below) from my US Patent 5,265,350 shows this angular relationship.

FIG 23A - 23BAs his ski changes edges, Ligety applies rotational force to his foot with the internal rotators in his pelvis; ergo he rotates his entire leg into the new turn. This action reinforces and drives pronation. The reason it works is that the actions are in phase and therefor complimentary with each other. Local Whistler ski pro, Ken Chaddock, describes this perfectly in his book, Ski Well Simply. The problem is that most skiers cannot make this move even if they know how because their ski boots are impeding the required joint actions.

It may be hard for some to visualize what I am describing. So I will try and generate some animated drawings for a future post to help explain this. If those who are teaching young racers how to ski can teach them the skimove in their formative years I believe it should be possible to produce a whole generation of Ligetys and Shiffrin’s.

 

12 comments

  1. I agree with cookiebewley about not levering the front of the boot but keeping up with the skis, I explain this as the standing up on the bus or tube (subway) game that most of us have tried. Can you stay in balance without holding on as the vehicle speeds up and slows down. The fore/aft moments we make in that situation are the same as on skis. Whenever the skis start to point downhill they are gonna accelerate so move forward to stay in balance. I introduce this concept from day one session one, gliding wedge in the fall line move forward to set off back when slowing down. Same in wedge to parallel to wedge drill. The movements are crude but the principles are there. By the time my clients are linking turns there is very little loss of fore/aft balance this makes turning the skis with the legs easier so I see less over rotation of the upper body and a quicker more flowing progression, not exactly ted ligerty but I hope you can see the connection

    1. Standing on the bus – great analogy. Or standing on the deck of a boat pitching and yawing in rough seas. Local Whistler Ski Pro Ken Chaddock (Ski Well Simply) describes it as standing on a magic carpet under the feet that is the zone of balance. The only thing attempting to lever the front of the boot accomplishes is to disconnect the skier from the snow. The idea that this somehow makes a ski turn or grip by applying force to the shovel is absurd. What is commonly referred to as ‘counter rotation’ of the upper body is also absurd. The key to generating edge-hold and turning forces on the outside ski is the layering rotational force on the outside leg by the internal rotators in the hip over top of the rotation into the turn both about the long axis of the ski (eversion) and about the horizontal axis (into the turn) due to to the outside foot pronating. This is often miscommunicated as actively rolling the ankle. When the skier makes the correct movement sequence the external forces acting on the skier cause the foot to pronate. This stretches muscles (eccentric contraction) that resist pronation. To some this appears as if the skier is rotating the hip towards the outside leg. I clearly show in my video sequences if Shiffrin that she rotates the outside leg into the turn. When I am more skilled at producing animated sequences I will generate videos that illustrate these movements.

  2. You keep talking about moving onto the ball of the old inside/new outside ski. Are you talking about pressuring this by rolling/pronating it or actually ‘standing’ on the ball of that foot?

    Rolling that foot and moving with the skis, but actually staying balanced on the arch will pressure the ball of that foot more.

    We have talked about moving to the new ski early for quite a few years – starting to move to the new foot right after the apex as you begin to flex, but not getting that foot dominant until right around edge change when you really start to roll that foot into the new turn.

    1. I plan to expand on this issue in future posts. From my perspective I see turns as one phase with transitions between turns. A turn ends when a skier starts to shift CoM to the inside ski while it is still on its inside (current edge). The new turn starts as the ski changes edges after going flat on the snow. I showed this in my analysis of Mikaela Shiffrin. As the ski changes edges Shiffrin appears to be standing perpendicular to the slope of the hill. In fact, that is precisely what she is doing due to the external forces acting on her. Insofar as pronating the foot the skier is moving forward in the hips (CoM) as the ski is rotating towards full contact with the snow. The skier needs to create pressure and move CoM forward. They do this by initially extending the knee. As the ski flattens on the snow the ankle must be able to dorsiflex. This is where most skiers run into problems. There is only a very small window in which to move forward in the hips so that CoM ends up in the same (sagittal) plane as Centre of Pressure (CoP) which will end up under the ball of the big toe. If the shaft of the boot presents significant resistance to the movement of the shank that accompanies ankle dorsiflexion they cannot create the movement that will cause the foot to pronate. Note that the skier does not ‘roll the ankle’ as many believe. The other thing that is key is that as moves on an arc from the heel to the ball of the foot the skier simultaneously rotates the entire leg into the new turn with the internal rotators in the hip. Local Whistler Ski Pro, Ken Chaddock who wrote the book Ski Well Simply figured this out on his own. Chaddock also talks about feeling pressure under the heel and ball of the foot. He is describing pronation. Chaddock also says that he never feels the cuff of the outside boot either fore-aft or side to side. This is a good example of how someone will make what are intuitive moves if they are able to do so. So essentially we you and I are saying the same thing. If you combine the active application of rotational force into the turn with the hip rotators with pronation which is passive and results from a movement sequence you will realize the power those such as Ligety can apply to a ski.

      1. I think we perhaps are indeed describing somewhat the same movement patterns, but with a slightly different concept of the location of the center of mass relative to the foot. It could be that, as an instructor at Jackson Hole, I try to keep descriptions in terms that are easily understood and, most importantly, easy for people to feel and hence do.

        I do agree with the term “move forward”, but only in as much as I want to describe the “keeping up with, centered and balanced” on the skis. I do not want to have people pressure their tips, or the balls of their feet by trying to lever forward. I want them to stay balanced over their feet.

        The sweet spot of the foot is generally the back part of the arch, forward part of the heel, right where the weight comes down to the foot from the tibia.

        Directing people to pressure the balls of the feet, hinders them from flexing the ankle and being able to stay in balance over their feet. That is why I made the previous comment about “moving forward” and ball of the foot.

        I agree that you do not roll the ankle, but rather I want people to learn to roll their feet, articulate, their feet inside their boots. Hence, I agree that there needs to be room with a more pliable, flexible foot bed for this to occur. For most people, if I ask them to feel their foot rolling onto their arch, and then to pay attention to the pressure created under the ball of the foot, they will pronate and edge the ski.

        The moving forward, is with the skis. I like to compare it to jumping down the hill off your new foot at the top of the turn, a slow motion, controlled jump, propelling you into the turn, foragonaly, but balanced with the skis.

        Regarding the weight transfer foot to foot, it is continual and progressive. Instead of dividing a turn into a beginning and an end, with phases such as initiation, completion, etc. I prefer to describe it as finishiation. There is a difference in timing of your upper versus lower body. They are taking different lines, coordinated, yet they each start the turn at different times. Your center of mass is beginning to move into the new turn as soon as you start to flex while your skis/legs are still in the old turn. This is the same time that you start to move to your new foot, when you start to flex to manage the pressure of the turn forces.

        Your skis start moving into the new arc at edge change, however, the weight transfer started moving to your new foot way before edge change.

        So the timing of when the skis start the new turn is at edge change, whereas the timing of when the center of mass starts the new turn is right after the apex when you start to flex.The timing of when you start to move to your new foot is right after the apex, when you start to flex, however, that new foot is not dominant until around edge change (either a bit before or a bit after). So, functionally, the beginning and end of a turn depends on what part of the body you are looking at – finishiation!

        So, yes, I think we are saying similar things, but I am very wary of ever telling anyone to move forward, instead I say stay with your skis and go where they go… However, I agree that sometimes, we ‘lead’ our skis, but I disagree in pressuring their tips and putting weight either forward onto the balls of our feet or the tips of the skis. This is a fine point, but I believe a very important one when coaching people the timing and direction of their movements.

        Thoughts?

  3. You keep talking about moving on the ball of the new outside foot/old inside foot. Are you meaning moving to the ball by rolling/pronating the foot onto the new edge or do you actually mean putting weight forward onto the ball of the foot. Both will result in more pressure/weight on that foot, but both are very different. I hope you mean rolling/pronating and then moving forward with the skis/foot into the new arc.

  4. Due to massive over pronation I have a canting device AND a footbed in order to get close to alignment in my boots. this obviously prevents the foot pronating as you described. Without this stuff my inner calf is hard up against the side of the boot. Any suggestions? ?

    1. A lot depends on how you define over pronation. In my posts I have stressed the importance of functional feet with the right shape of legs as a prerequisite to be able to ski with ease. There are people who have feet that are considered flat that may be quite functional. My approach is to build the configuration of the boot around a skiers’ leg geometry. I start the process by establishing a net ramp angle (boot ramp + binding ramp) of 3-4 degrees. Then I set the cuff at the right forward lean and side cant angles. This is often much harder than it sounds. At some point I will post photos and a discussion of what I had to do to my wife’s boots so she could ski with a technique that allows her to engage the external forces to support balance and drive her outside ski. There is no way I could get the configuration I needed with the stock adjustments in the boot. I had to disassemble the cuff, cut away portions of the cuff and lower shell, then reassemble the boot with T-nuts. Once I had removed the cuff from both boots I had her stand in the shell bottoms with the right angles of her knee and ankle with nothing under her feet (I will discuss this in a future post). Then I trimmed the cuffs as necessary to get it to sit properly on the shell in relation to her legs. I normally set the cuff side cant so the cuff is centred on the legs when the person is standing on 2 feet with the weight equal on each foot. If they have a large calve, I may set the cuff so it has slightly more space on the outside of their leg than the inside. When I was doing a lot of boot modifications in the late 1970s and early 1980s there were some cases where I had to cut parts from several pair of boots and plastic weld them together to make an entirely new boot. From time to time, I get asked by a friend to help them find and set up with a new pair of boots. The biggest challenge I face is finding a pair of boots that I can successfully work with. If you haven’t already done so, standing in the bare shells with our feet hip width apart and the buckles closed to the first bale catch is a good way to get an idea of your issues. In my experience trying to get the foot to fit the boot with wedges, footbeds etc. tends to compromise foot/lower limb and especially balance functions.

      1. Many thanks for the prompt reply, the pronation comes from sub talus and navicular, this over the years has created wear on the medial side of the articulating surface of the knee this in turm creates a bow leg effect at the knee despite the 9 degrees of over pronation on the foot. I’ve just made a footbed that supports the sub talus and the medial arch but with little contact with the inside edge of the
        foot.
        I know this sounds unstable but it feels better than anything else I have tried

      2. At some point you have to do what works. There are some excellent papers on exercises to improve foot function such the short foot. An excellent paper on this subject is ‘The foot core system: a new paradigm for understanding intrinsic foot function’ (Br. J Sports Med). Here’s a quote: “The movement and stability of the arch (of the human foot) is controlled by intrinsic and extrinsic muscles. However, the intrinsic muscles are largely ignored by clinicians and researchers. As such, these muscles are seldom addressed in rehabilitation programmes. Interventions for foot-related problems are more often directed at externally supporting the foot rather than training these (intrinsic) muscles to function as they are designed.” When I started skiing in 1971 my feet were far less functional than they are designed”. From about 2005 I have gone barefoot as much as possible as well as wearing shoes such as the New Balance Minimus. As the shape and function of my feet have improved so has my skiing ability.

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