Ankle Flexion--Active or "Passive"?

Sanity

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What I mean is how you look at the relationship cuff pressure and force on the ski. Studies have shown that cuff pressure does absolutely nothing for pressuring/bending the ski. The ski bends because of force. Centripetal force, gravity, your weight etc... The position of your CoM decides where that ski is going to bend, because (to simplify, not entirely accurate, cause not all those forces move in the same direction) that is where all those forces will be doing their work. It so happens to be that if you want to bend the ski a lot, you want to position your CoM in a way where it is likely that at some point in the turn you are going to feel shin pressure. That shin pressure however is a result of the position of your CoM and not a goal in itself. The shin pressure in itself does nothing. I could mount your binding position all the way to the back of your ski and you can ski with all the shin pressure you want and you'll never be able to ski the same radius as someone with a neutral position, with little cuff pressure and the binding mounted in the 'middle' of the ski if both skiers are skiing on the same ski. What a ski boot does do is that it absorbs loads that are being exerted on the skier. So a ski boot in that sense makes life easier for us, and that is what gives the power feeling. But in theory you should be able to ski exactly the same with unbuckled boots.

Hence shin pressure is never the goal. There are 100 ways to have shin pressure and I could contort my body in all kinds of ways where I would have shin pressure with a CoM that is extremely far back. I could for example bend my ankles a lot to the point I would have shin pressure, but then bend my knees even more to a point where my whole body from the knees up will be in the backseat. Even though I would have shin pressure, that would be very counter productive. On the other hand I could also have shin pressure by leaning into the cuff and skiing like Michael Jackson. Same deal, I would have shin pressure, but it would be counterproductive. Being centered is key, and once you're balanced and centered everything else doesn't matter. Sometimes being centered means there will be shin pressure, sometimes being centered means there won't be any shin pressure. So the important nuance is about the relationship CoM and shin pressure. I want my CoM in a good position and then I'll probably end up with some shin pressure some of the time instead of I want shin pressure and we'll see where my CoM ends up.

Maybe @Jamt you still have some of those boot/interface studies at hand? I have a new computer and lost a lot of my files.


I would love to see that study, cause from what I know that is not necessarily true. The only study I know of that sort of looks at bending the boots is the Birdcage-experiment (1988?). And even that didn't really look at bending the boot, but at pressuring the boot. The WC skier was skiing very neutral. All other studies I know of that study boot/ski interface and all things related look at loads (as in force) and not at the degrees a boot is bent.

I'm aware of certain groups of skiers that advocate a centered position, but for competition mogul skiing the goal is to pressure the shins, and it does have real physical benefits, because it increases pressure on the tip of the ski. Olympic mogul skiers will tell you to pressure the shins for short radius turns. You can turn sharper by pressuring the tip. Also, the tip digging in can provide speed control on the backside of the bump. One way to visualize it is to imagine that the ski is tipped with a steering angle at the beginning of the turn. If you can apply pressure to the tip it will bite and bend. Once bent, the ski will arc according to that bent radius. I believe your analysis is entirely based on sidecut, and that's an ideal approximation to a good carved turn, but ultimately in real skiing there are many factors that control a turn. If you just want to do perfect RR track turns with a carver ski on the groomed, then centered is best, but if you want to try to get lots of different types of performance out of the ski based on different circumstances, then you may want to apply shin pressure at times. If you want to do quick short radius turns with speed control on a mogul ski, then you definitely want continuous shin pressure.
 

Sanity

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I would love to see that study, cause from what I know that is not necessarily true. The only study I know of that sort of looks at bending the boots is the Birdcage-experiment (1988?). And even that didn't really look at bending the boot, but at pressuring the boot. The WC skier was skiing very neutral. All other studies I know of that study boot/ski interface and all things related look at loads (as in force) and not at the degrees a boot is bent.

https://www.researchgate.net/public...oratory_flexural_behavior_of_alpine_ski_boots
 

Noodler

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And this is what happens when we take a highly dynamic sport and talk about it as if we are doin the "Hokey Pokey" dance. Try setting resultant objectives like (if your intent is to carve) lifting your edges and getting your skis out and away as early as possible.... and when successful, then maybe think about the kinetic chain that got you there.

What in the world does that have to do with boot setup and stance alignment? I wasn't referring to the act of skiing and how to make turns. You're trying to pull in some controversy here that didn't exist.
 

Noodler

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I'm aware of certain groups of skiers that advocate a centered position, but for competition mogul skiing the goal is to pressure the shins, and it does have real physical benefits, because it increases pressure on the tip of the ski. Olympic mogul skiers will tell you to pressure the shins for short radius turns. You can turn sharper by pressuring the tip. Also, the tip digging in can provide speed control on the backside of the bump. One way to visualize it is to imagine that the ski is tipped with a steering angle at the beginning of the turn. If you can apply pressure to the tip it will bite and bend. Once bent, the ski will arc according to that bent radius. I believe your analysis is entirely based on sidecut, and that's an ideal approximation to a good carved turn, but ultimately in real skiing there are many factors that control a turn. If you just want to do perfect RR track turns with a carver ski on the groomed, then centered is best, but if you want to try to get lots of different types of performance out of the ski based on different circumstances, then you may want to apply shin pressure at times. If you want to do quick short radius turns with speed control on a mogul ski, then you definitely want continuous shin pressure.

You're on a roll today... :)
 

Skitechniek

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I'm aware of certain groups of skiers that advocate a centered position, but for competition mogul skiing the goal is to pressure the shins, and it does have real physical benefits, because it increases pressure on the tip of the ski. Olympic mogul skiers will tell you to pressure the shins for short radius turns. You can turn sharper by pressuring the tip. Also, the tip digging in can provide speed control on the backside of the bump. One way to visualize it is to imagine that the ski is tipped with a steering angle at the beginning of the turn. If you can apply pressure to the tip it will bite and bend. Once bent, the ski will arc according to that bent radius. I believe your analysis is entirely based on sidecut, and that's an ideal approximation to a good carved turn, but ultimately in real skiing there are many factors that control a turn. If you just want to do perfect RR track turns with a carver ski on the groomed, then centered is best, but if you want to try to get lots of different types of performance out of the ski based on different circumstances, then you may want to apply shin pressure at times. If you want to do quick short radius turns with speed control on a mogul ski, then you definitely want continuous shin pressure.
Yes, completely agree! The part in bold is the key sentence here. Also in short turns you can make use of this sidecut effect, although it does not work quite the same as with carving. With skidded turns, if you want to use the sidecut effect, what you need is the resultant force of the impacting snow acting on the tip of the ski to be bigger than the resultant force of the impacting snow acting on the tail of the ski. You only need very little tail displacement for this effect to take over, couple centimeters is enough.

When I ski moguls I also try to be more forward, but my movement pattern completely changes when in the moguls compared to outside of the moguls. In moguls, especially comp mogul skiing, there is a lot of active femur rotation going on, which is heel pushing. Moguls is a bit like oldschool wedeln in that regard imho. If you are more forward, the tail of the ski becomes lighter and it becomes easier to heel push. Side cut and the resultant force model I described only work up to a certain radius. Once you want to ski a turn smaller than the ski radius is capable of, you will have to resort to muscular input to make the turn smaller. But outside of the moguls that is not a style of skiing I aspire to. And that style of skiing is strictly forbidden when you ski moguls in a ski instructor course btw.

But yeah, we are in total agreement here.
Thanks, will read!
 

Tony S

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And this is what happens when we take a highly dynamic sport and talk about it as if we are doin the "Hokey Pokey" dance. Try setting resultant objectives like (if your intent is to carve) lifting your edges and getting your skis out and away as early as possible.... and when successful, then maybe think about the kinetic chain that got you there.
Your advice is basically "First go out and link some awesome turns and then figure out how you did it so you can tell others what to focus on." That's great if A) Your audience consists of instructors and B) they all already know how to achieve the result. In the case of this forum neither A nor B is true. So we're back to "how do I get there in the first place?"
 

Sanity

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Yes, completely agree! The part in bold is the key sentence here. Also in short turns you can make use of this sidecut effect, although it does not work quite the same as with carving. With skidded turns, if you want to use the sidecut effect, what you need is the resultant force of the impacting snow acting on the tip of the ski to be bigger than the resultant force of the impacting snow acting on the tail of the ski. You only need very little tail displacement for this effect to take over, couple centimeters is enough.

When I ski moguls I also try to be more forward, but my movement pattern completely changes when in the moguls compared to outside of the moguls. In moguls, especially comp mogul skiing, there is a lot of active femur rotation going on, which is heel pushing. Moguls is a bit like oldschool wedeln in that regard imho. If you are more forward, the tail of the ski becomes lighter and it becomes easier to heel push. Side cut and the resultant force model I described only work up to a certain radius. Once you want to ski a turn smaller than the ski radius is capable of, you will have to resort to muscular input to make the turn smaller. But outside of the moguls that is not a style of skiing I aspire to. And that style of skiing is strictly forbidden when you ski moguls in a ski instructor course btw.

But yeah, we are in total agreement here.

Thanks, will read!

Not all comp mogul skiers have the same style, but I don't heal push, and the top level coaches that I've seen don't do or teach a heal push. There is some rotary at the top of the turn when the ski tips are off the air. Some don't teach any rotary for the groomed run short radius turns. So, there are some mogul coaches that really just say forward pressure, knee angulation, weight shift, and let the ski do everything else. Merely, the forward pressure provides a quick, sharp turn.
 

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The inside the boot/outside the boot stuff is a little hard for me to digest, but either way, if I wasn't applying pressure properly from the foot then would I really be able to assess this angle and feeling accurately?
Not sure if this will help think about the inside/boot stuff, but being a visual learner I sketched this out in a super fancy program called Paint :D (while procrastinating on things I should be doing).

The first person has the "default" stance that the boot creates. The second person shows what happens when a lifter is added outside the boot, everything gets tilted together. The third added a gas pedal inside the boot, which tilts the foot up, but leaves the remainder of the boot the same. All angles are made up, just to exaggerate what is changing/staying the same.

1642186842847.png
 
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AmyPJ

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Not sure if this will help think about the inside/boot stuff, but being a visual learner I sketched this out in a super fancy program called Paint :D (while procrastinating on things I should be doing).

The first person has the "default" stance that the boot creates. The second person shows what happens when a lifter is added outside the boot, everything gets tilted together. The third added a gas pedal inside the boot, which tilts the foot up, but leaves the remainder of the boot the same. All angles are made up, just to exaggerate what is changing/staying the same.

View attachment 155174
LOL I love this! It's very high tech, too. Stick figures 101. :roflmao: I tried drawing the same thing for my husband but I confused myself. So, this drawing is perfect. It indicates that a gas pedal can absolutely throw one out of balance aft.
 

Rod9301

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I'm aware of certain groups of skiers that advocate a centered position, but for competition mogul skiing the goal is to pressure the shins, and it does have real physical benefits, because it increases pressure on the tip of the ski. Olympic mogul skiers will tell you to pressure the shins for short radius turns. You can turn sharper by pressuring the tip. Also, the tip digging in can provide speed control on the backside of the bump. One way to visualize it is to imagine that the ski is tipped with a steering angle at the beginning of the turn. If you can apply pressure to the tip it will bite and bend. Once bent, the ski will arc according to that bent radius. I believe your analysis is entirely based on sidecut, and that's an ideal approximation to a good carved turn, but ultimately in real skiing there are many factors that control a turn. If you just want to do perfect RR track turns with a carver ski on the groomed, then centered is best, but if you want to try to get lots of different types of performance out of the ski based on different circumstances, then you may want to apply shin pressure at times. If you want to do quick short radius turns with speed control on a mogul ski, then you definitely want continuous shin pressure.
True, but pressuring the cuff comes from pulling the feet back strongly as you crest the bump.
 

Skitechniek

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Not all comp mogul skiers have the same style, but I don't heal push, and the top level coaches that I've seen don't do or teach a heal push. There is some rotary at the top of the turn when the ski tips are off the air. Some don't teach any rotary for the groomed run short radius turns. So, there are some mogul coaches that really just say forward pressure, knee angulation, weight shift, and let the ski do everything else. Merely, the forward pressure provides a quick, sharp turn.
Rotary per definition is a heel push imho, so that is where we differ from viewpoint I guess. Rotary can never be towards the direction of travel, because you can't bury your edges further into the snow then they already are. If you turn left, rotary will be to the right. If your turn right, rotary will be to the left. It is the chain of muscles at the back of your body that cause rotary imho. Hamstrings, glutes etc... Not the front like the vastus medialis and quads.

If you are weightless and the skis are in the air rotary to the inside would be possible without destroying your knees, but that seems like a very counter intuïtive way to ski moguls to me. I never really tried skiing that way, but I am open to trying new things if that is what you are getting at?

But thanks for the insight!

Sorry for the thread drift, will shut up now. Back to ankle flexion!
 

Tony S

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Not sure if this will help think about the inside/boot stuff, but being a visual learner I sketched this out in a super fancy program called Paint :D (while procrastinating on things I should be doing).

The first person has the "default" stance that the boot creates. The second person shows what happens when a lifter is added outside the boot, everything gets tilted together. The third added a gas pedal inside the boot, which tilts the foot up, but leaves the remainder of the boot the same. All angles are made up, just to exaggerate what is changing/staying the same.

View attachment 155174
I love the pic but is "gas pedal inside boot" an actual thing? How would that be realized? Seems like you'd either need to lower the boot board in the heel (not "heal"!!!!!) or else have to have a whole lot of extra toe height in the shell to raise the BoF.
 

Sanity

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Rotary per definition is a heel push imho, so that is where we differ from viewpoint I guess. Rotary can never be towards the direction of travel, because you can't bury your edges further into the snow then they already are. If you turn left, rotary will be to the right. If your turn right, rotary will be to the left. It is the chain of muscles at the back of your body that cause rotary imho. Hamstrings, glutes etc... Not the front like the vastus medialis and quads.

If you are weightless and the skis are in the air rotary to the inside would be possible without destroying your knees, but that seems like a very counter intuïtive way to ski moguls to me. I never really tried skiing that way, but I am open to trying new things if that is what you are getting at?

But thanks for the insight!

Sorry for the thread drift, will shut up now. Back to ankle flexion!

I only do rotary when I'm weightless during transition or when there's just a sliver of snow underneath the ski under the binding with the tails and tips in the air. There are a bunch of other non-comp mogul skiers that talk about active steering and rotary along the length of the ski, not a heal push. We were just talking about this in that Berger thread.
 

Seldomski

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Rotary per definition is a heel push imho
Disagree, rotating a ski does not imply heel pushing. If you are forward enough, the tail edges will not be strongly engaged with the snow and the ski loses grip at the end of the carve. It may look like a heel push, but it's the ski sliding out. And yes there are skiers that actively heel push to slow. You can do whirly birds down the fall line without heel pushing.

Back to dorsiflexion - it's a way to help get centered on the ski and use the entire edge of the ski in the turn. Some techniques in moguls use mostly the front of the ski and so you have to get really forward, and this is where I think strong cuff pressure as a cue works better for me than strong dorsiflexion. However, I caveat this with the fact that I am objectively not the best skier on the mountain :).
 

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I love the pic but is "gas pedal inside boot" an actual thing? How would that be realized? Seems like you'd either need to lower the boot board in the heel (not "heal"!!!!!) or else have to have a whole lot of extra toe height in the shell to raise the BoF.
Yes, I agree...you'd be more likely to lower your heel, rather than raise your toe inside the boot. But same outcome (probably wrong terminology on my part).

For this example I wanted to show a direct relation to inside/outside the boot where AmyPJ was talking about gas pedals, I thought I'd show the toe specifically.
 

razie

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I've been really playing around with ankle flexion in the past week or so. I've always done what I will refer to as "passive" ankle flexion where I allow my body weight to push forward against the boot, resulting in a flexed ankle. So much instruction seems to teach this, but maybe I've misunderstood it. Or maybe because I'm so flexible, shin/tongue pressure created this way doesn't create enough tension in the foot/ankle/achilles.

I started to actively dorsiflex using the tibialis anterior muscles, particularly at transition, and it seems to be eliminating my old stem habit and also keeps me in a much better stacked position. It has also highlighted the fore/aft balance issues I continue to have which I am going to have addressed soon (have new shells, same as current shells.) When I say active, I mean that I am really using the tibialis anterior to forcefully pull my foot up. The issue I feel with this is you can't pressure the big toe while actively dorsiflexing. It's impossible. It DOES put passive pressure on the ball of the foot. One physically cannot actively dorsiflex and push down on the ball of the foot or toes.

This latest video from Deb Armstrong got me to really thinking about it as he talks about how the body senses when it's in balance. It cannot perform at it's highest level when it is out of balance. My boots are not putting me in balance. I can sense that so am always a bit tense and really struggle in variable conditions. The last time I felt balanced in boots was in a pair of Salomon XMax. They are far too big volume-wise for me, hence why I am in a race boot (Rossi ZJ+.)
:thumb:

Shin contact and active dorsiflexion are basic and undisputed. Here's a cue to try: don't think you're lifting the toes/foot. Try to bring the shins forward instead, ignore whether the foot lifts or not. That also helps keeps the foot back - like the guy says, a good thing. My normal thoughts are on heels and shins normally. However, unlike he says - do it when the leg is not "strong" yet. But before it becomes "strong" ;) . Once it's strong it's too late, the turn is about to end...

The bigger issue for you is to get balanced fore/aft in the Rossis. You need to do that to improve, I would say that's your biggest issue. The entire thing is complex, but some simple things can be done first: play with the cuff, open the buckles and see if it helps. Change the position and/or strenght of the strap. Spend 20$ and try some 5mm heel lifts stuff like that. Ideally, you'd look at the deltas and omicrons and other greek parts of the binding and boot. :geek:

I would not neccessarily use the bands. I can see their use: they add the focus on the tension that you normally need, but you don't normally have to fight a band... for instance: a narrow stance is not obtained by fighting a band that pushes your legs "in" but by keeping them "in" - it's the opposite muscle activation so here using a band teaches the wrong thing (try to squeeze a sponge between the boots instead, that's a better activation). However, if you try it for tipping the inside foot for instance (via the knee leading artifact thing I don't like), it may add that extra focus on the activation needed. Just think your way through it.
 
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Noodler

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Yes, I agree...you'd be more likely to lower your heel, rather than raise your toe inside the boot. But same outcome (probably wrong terminology on my part).

For this example I wanted to show a direct relation to inside/outside the boot where AmyPJ was talking about gas pedals, I thought I'd show the toe specifically.

The stick figures were awesome. Nice job. Note that we don't usually referring to an increase in height of the bootboard toe as a "gas pedal". That term is usually reserved for a lifter placed under the boot sole toe.
 
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AmyPJ

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:thumb:

Shin contact and active dorsiflexion are basic and undisputed. Here's a cue to try: don't think you're lifting the toes/foot. Try to bring the shins forward instead, ignore whether the foot lifts or not. That also helps keeps the foot back - like the guy says, a good thing. My normal thoughts are on heels and shins normally. However, unlike he says - do it when the leg is not "strong" yet. But before it becomes "strong" ;) . Once it's strong it's too late, the turn is about to end...

The bigger issue for you is to get balanced fore/aft in the Rossis. You need to do that to improve, I would say that's your biggest issue. The entire thing is complex, but some simple things can be done first: play with the cuff, open the buckles and see if it helps. Change the position and/or strenght of the strap. Spend 20$ and try some 5mm heel lifts stuff like that. Ideally, you'd look at the deltas and omicrons and other greek parts of the binding and boot. :geek:

I would not neccessarily use the bands. I can see their use: they add the focus on the tension that you normally need, but you don't normally have to fight a band... for instance: a narrow stance is not obtained by fighting a band that pushes your legs "in" but by keeping them "in" - it's the opposite muscle activation so here using a band teaches the wrong thing (try to squeeze a sponge between the boots instead, that's a better activation). However, if you try it for tipping the inside foot for instance (via the knee leading artifact thing I don't like), it may add that extra focus on the activation needed. Just think your way through it.
So you’re saying active dorsiflexion. You describe what I’ve been playing around with-actively tensioning the tib anterior vs. focusing on lifting the toes. For whatever reason, that cue works for me, maybe because that muscle in me is really strong from riding horses for so many years. It has changed my turn dynamics quite drastically.

The alignment is getting closer. Having two boot shells to experiment with will be fun. ???
 

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Once someone has been taught to pressure the boot, it might be fun for some to argue against it but it’s not usually where the op is leading ( maybe it is here). So just because at my last 1/2 day lesson with a l3 examiner he instructed the shin pressure, doesn’t mean it’s the only way, just accept it is a way.
 
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