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# Taking a stand on the stability issue...

In another thread, DavidM said, “My issue is the ability to develop the most stable platform available under foot.”
So, this got me thinking.
First off, we’re not talking about walking, or running, etc. Let’s look at a stationary human. (this could turn in to a new theory – “The Differential Calculus of Human Movement”).
I want to look at a stationary human, because skiing is not like walking/running from the point of view of large movements of one side of the body compared to the other, but of having a stable platform created by smaller movements.

Preliminary notes:
In the following discussion, I’m talking about the skeletal frame, without the use of muscles to interfere with the natural situation, and I’m considering that the surface being stood on has a very high coefficient of friction, i.e. the person is not going to slide off it, or is perhaps fixed to it.

Basics: Stage 1
Standing on a horizontal surface.
Human beings tend to stand vertically. For balance, you stand over your feet, i.e. the Centre of Gravity needs to be acting over the area of support. If you stand on a horizontal surface and lean too far forward, too far back, or too far to the left or right, you lose your balance. In a natural state, the best option for a biped is to spread their weight evenly over both feet, with the CoG acting through a point equidistant between them. Once the CoG falls outside the area of support, the ability to maintain verticality no longer exists, and the body assumes a more horizontal pose. Technically, we in the business refer to this as “Falling Over”.

OK, now for stage 2…
Standing on a non-horizontal surface.
When standing on a slope, we tend to stand vertically. Not necessarily at right angles to the ground. We stand at an angle to the slope we’re on, but relative to the horizontal, we are still at right angles. In this case, the CoG acts vertically down again, through the area of support, but the line from the CoG through the area of support is not perpendicular to the slope, but perpendicular to the horizon. In this instance, again, the best option is to spread the weight evenly over the two feet. (this will not be the case if the surface is low friction)

Stage 3. (a bit more complex)
Replicating, while stationary, the forces created when turning.
In another thread, I talked about banked tracks, and their effect on turning, because they spread the forces more evenly, and allow the maintenance of higher speeds. If you have a reverse camber bend, i.e. one that is high on the inside, and low on the outside, it is more difficult to keep traction, or speed, as you go round it. This is because the bend is now acting in conjunction with the centrifugal forces to create a large resultant, which mean flying off the track is more likely. The angle of the slope accentuates the bend. Working back from this, it is possible to replicate the forces involved in turning by standing on a slope. To be perpendicular to the slope will mean you fall, so an angle to the slope must be created to get the CoG to lie within the area of support, as discussed above.

Now comes the differential calculus bit…
When skiing the body itself does not move very much relative to the skis. The skis move on the snow, but the body is fixed to the skis. Let’s break the skier’s movement down to stationary components, rather like a series of frames of a film. What is experienced by the body are a series of slopes of different angles. Some are due to the shape of the hill, some are due to the effect of turning, and some are due to a combination of the above. It may not LOOK like this, but that is what is happening, based on my comments above.

So, that’s my theory, and I expect the main point of debate will be over the phrase in stage 2:
“the best option is to spread the weight evenly over the two feet”.

The question is, “Is this correct?”

Well, I’m not sure. I do know that maximum stability of any stationary object occurs when the CoG acts through the centre of the area of support, but this does not mean that we, as sensate beings obey that rule. Perhaps our brains override the best solution with one which fits our world view, so we no longer spread the load evenly and put more weight on one support than the other.

Where do you stand on this issue?

S
Fox,

While I agree with you that skiing is not very much like walking or running, neither do I think starting with a model of standing in balance is adequate. The history of the fields of kinesiology and movement science are filled with extrapolations from analyses of static situations. My impression is that as a generalization these have not proven to be very accurate or useful. I think the same is true for skiing. Unless we include dynamic and kinematic considerations in any model of skiing I think it is very likely that we won't be very successful. That doesn't mean it isn't useful to consider the simplified static case (as you've done) but I think this is likely to be of most use when considered as an exercise of comparison with the real world of dynamics and kinematics. Further to this I also strongly believe that without also adding in considerations of human perception we will also severely limit any type of analysis of skiing movement and technique.

With all that said I personally have focused less on technique and movement analysis and more on feelings and perceptions as I have evolved over time in my own personal skiing.
Si,
I agree, and in an earlier thread, I argued about the big differences between static and dynamic balance. I am trying to extend part of the DM discussions on balance. He likes to go back to walking, but I see very little of walking movements in skiing.
He had mentioned stability, so I was trying to look at the skier as an isolated stable system.
I think part of the issue actually lies in how different people ski, and how we perceive it. David has mentioned in several threads about weight transfer from one ski to the other, and (correct me if I'm wrong, DM), would be more of the opinion that turning involves using the outside ski in the main, whereas I would have thought that using both would be better.
I was trying to show in a simplified way what I meant, and why I felt that using both skis would be better. If you read my posts in the other recent balance thread, where I talk about turns, and banking, it may help to understand what I meant.

Thanks again, and keep up the comments, cause I'm trying to learn.

S
Well, Nice work Fox

On this subject.

In situations of dynamic equilibrium, I feel much better with forces committed to one leg at a time, but in continuous transition between the two. This allows me to do whatever I must with the free leg to regain anything that may be lost. If I have both feet grounded. I have nothing left to move. This I call being caught flat footed.

I know my dynamic balance is NOT enhanced by maintaining my CoG inside my base of support. Rather, all dynamic motion is a leap from one position of support to another, in a flow of motion.

Regards

CalG
Fox, Si, CalG,
I think you all hit on the key that the dynamics of skiing are what it is all about. Good skiing is not as much about being stable as it is about managing instability. If you focus on being in balance for any given moments conditions "now", by the time balance zeroes in, it is "then", in the past, history, too late. In skiing I think it is important to invision balancing for the future, creating a proactive process, of anticipation, to facilitate a flowing interaction with all the forces involved vs. reactivly chasing static balance or stability.

How many skiers would use adjectives like "stable" or "balanced" to describe what the enjoy about skiing? "Ah, the thrill of a stable balanced stance!" :

Most of my time skiing is spent falling, the fun is in learning to catch myself as smoothly, and as briefly, as possible.

Skiing could be likened to flying on the face of the earth in an environment of energy. The greatest stability is exhibited by proactivly managed flow of CM and it's relationship to that surface, not from planted feet. Birds exhibit stability in flight as this concept. Fish exhibit stability swimming in flowing water as this concept. Great skiers flow (guide their CM) with the same kind of synergy within their environment.

In akido balance comes not from meeting force with counter-force or resistance, but from melding with it and re-directing it's flow as desired.

[ January 22, 2003, 10:45 AM: Message edited by: Arcmeister ]
Arc, I like it!

As a follow up I would say that from a personal perspective I am more and more coming to believe that "rhythm" is perhaps a better way to think about some of the key issues in skiing. From an instructional perspective I think the focus is on teaching movements and helping skiers to get the feel of those movements. However, it's mostly the skier themselves who have to discover how to integrate those movements into rhythms. Somehow I think that a lot of the very best skiers (and great athletes in other sports) have an exceptional ability to discover and reproduce those rhythms for themsleves. I most enjoy working with coaches and instructors who recognize and communicate about the nature of the role they play in this regard and the role of the student to take it from there. It's why following an expert skier closely can play such an important role as it pushes a skier to find a rhythm (emulation of a lead skier being helpful in this regard) because movements alone don't do it.
Fox,
Let me pick up "When skiing the body itself does not move very much relative to the skis.". I agree with the above said, there's a moving motion in carved turns. This IMHO basically a play with three forces:
1. the good ole gravity which pulls you downhill
2. the momentum to keep you on the direction you're heading
3. the forces you apply vs. 2. (maybe 1., if you don't let the ski's "go") in order to change direction, i.e. turn
There's not much you can do about 1. and 2., they are existing at a given point in time. All you work with is 3. If you keep your body relative to the skis, that's a whole lot to do: You have to muscle against the forces of your momentum, and hope the edges will hold, with expectations diminishing for the latter over the course of the day as the snow gets beaten up by riders, skiers and the sun.
What Bode, Hermann and friends are doing is to utilize their body weight by leaning the lower body into the turn. Shoulders and hands are involved for fine tuning the balancing act. This way, Bode lightens up his edges, because they now do not have to transfer the entire force required to guide the (shaped!) skies through the turn. I've taken a pic of Bode from one of the previous threads about stance, and added, based on the skier's center of gravity:
1. Blue: Gravity force
2. Red: Momentum
3. Green: Forces vs. momentum: Body weight, and edges' grip

Noteworthy also, i think, is that the angle Bode is skiing the edges does not result from an attempt to tip the edges, but rather from leaning into the turn the way he does. I think of the system as a three-piece pendulum with the lower body being the middle piece, with legs and skies attached to one, shoulders and arms attached to the other end.

Just my 2 cents
jpfeiffer,

In the frame that you are adding your lines too there is no momentum in the direction that you have drawn your red line. Bode has stopped his right to left momentum and is about to begin to move from left to right. The momentum of his body at that point is down the fall line.

Also, leaning the body inside the turn produces no force line as you depict it just leans the body into the turn in relation to the feet. Without skis on the feet leaning like that would not change your direction it would only put your hip and torso on the snow. It is the skis that produce the force vector that we use to change the direction of travel of the CM. The greater the speed and the higher the edge angle the greater the force vector produced by the skis. By being so far inside and so extended Bode is able to make the maximum use of this force to accelerate his body fron the left to the right and use stacked bone to transmit the force rather than muscle. It was this misunderstanding of physics that lead to the idea that one could ski by leading with the CM and that the skis would be pulled along behind. We aren't pulling the skis. The skis are pushing us.

Yd
Fox,

Here is another way to look at it.

Drop a plumb line from your center of mass. In the static situations you are talking about the line falls directly down from the CM to a point between the feet. Motion such as skiing will make the plumb bob sway from side to side. One of the goals of skiing is to keep this imaginary plumb bob between my feet by moving my center of mass to the right or left of my base of support.

Yd
Ydnar, I used the wrong term(s), i have to correct myself. Did not want this to become too scientific [img]smile.gif[/img] . Red is the centrifugal force which still exists at that point, countered by the centripetal force (green) consisting of partly the body weighting into the turn and partly force transferred through the edges. The skies carve through the turn, which, you put it nicely: "produce the force vector that we use to change the direction of travel of the CM". This vector, i think, is the addition of all three force vectors, and that one lucky skier wins the race, which manages transition of it through time under the boundary conditions of the race course in the most efficient way.
I sidetracked... I actually try to use my body weight for distribution of the centripetal force away from the edges. As a result, the edges "lighten up" (for lack of better term, taken from my perception). This helps, for example, at the end of a busy, sunny, perhaps windy day, when the edges don't hold as good as they did in the morning. I try to counter the centrifugal force with my body weight, and i'm back in business: The skies carve through the turn, nice and light, while i hear those ugly Eastcoast skiing noises all around me. That's what i see the racers doing, too - i think looking back in the thread where i took the original picture from, it looks more obvious in Hermann Maier's turns.
The more i believe to know, the worse, in my perception, is my own skiing. But i'm working on it. [img]smile.gif[/img]
It looks like Bode's plumb bob would often swing way outside his feet!

It's interesting how these slalom images often look similar to bump skiing. In images 3,4,5 above of Bode he looks quite similar to a bump skier. Ron LeMaster talks about the "virtual bump" at the end of the turn and there's a good image of it. I suppose the tremendous acceleration of the slalom skis and the need to cross the skis under quickly leads to such positions.

I wonder how "stable" Bode feels?

Quote:
 In skiing I think it is important to invision balancing for the future, creating a proactive process, of anticipation, to facilitate a flowing interaction with all the forces involved vs. reactivly chasing static balance or stability. -Arcmeister
I love this statement!
I think in skiing the farther you are from your feet the more fun it is. (even though it's often scary) The process of chasing the "balancing act in the future" is really quite addicting. However, tighten down your boots way too much and that chasing of the balancing act isn't nearly as much fun or as successful.

I still suspect that DavidM is correct in saying that the body needs a stable platform however brief it is,(and it could be very brief indeed), to function optimally. How this works I don't know but it sounds quite correct. I mean gymnasts aren't exactly stable when they're doing flips etc. but I think they need a good "home" reference from which to function.

When you're running in a riverbed feet going from rock to rock and only touching very briefly that isn't static balance either. The function of the foot is very important there. It just needs a momentary input to do it's thing. Do something to impede the function of the foot though- like wearing a shoe that's much too small and it becomes much more difficult.

A stable foot is not necessarily static.
jpfeiffer,

your gravity vector is inaccurate. it would demonstrate force at a more oblique angle since the skier is moving downhill. gravity not only pulls him toward the earth's core, it also pulls him downhill.

otherwise, I like your graphic. [img]graemlins/thumbsup.gif[/img]
One short note to Yadnar's post. Bode is moving from left to right between the 4th and 5th frame. Only from the camera's perspective, is it in the last frame.

In Arc's comment about always being out of balance and seeking balance... I've heard that before, and really like it. But to elaborate on it a bit more, I think we need to think of balance in 2 different ways. There are proactive and reactive balance and imbalance moves that we make. When we are straight running, and we want to turn, we intentionally make a proactive imbalance move, to throw our balance off, so that we will be able to counteract the forces that build up in the turn. When some surface condition makes our skis do something we didn't expect, we reactively try to gain back balance. As we decide we are done with turn A, we bring ourselves out of balance, proactively, so that we stop turning. Then, if we decide to enter into turn B, we continue that proactive imbalance move across our skis, so that we can counteract the forces that we know will build up in the new turn. It' not unlike sprinting from a standing start, where you must first move the CM forward, so that your feet don't just run out from under you.

What is it really? We call it commitment (or maybe just a contribution, said the pig ).
John,

In the fifth frame Bode has changed his edges for the new turn but he is continuining to move across the hill from the right to the left. He will continue to travel from right to left untill he has used the force generated by the skis to slow and then stop the right to left component of his motion. At that point he can begin to accelerate himself back across the slope from the left to the right.

Think of it this way. The first half of what most people would call a right turn is devoted to decelerating the tranverse (across the hill from right to left) component of the skiers motion, the second half is spent accelerating the skier back across the hill from left to right. At that point the skier again changes edges (begins a "left turn") so that he can slow and stop the left to right component of his body's motion.

What really blows me away is that I can go from traveling across the hill at 25 mph from right to left to going 25mph from left to right in less than five seconds. Thats like going from 0 to 50 in a car in the same length of time.

Hope this makes what I was saying clearer,

Yd
Great thread Fox Hat! [img]graemlins/thumbsup.gif[/img]
I like all of the following statements:

Si: Unless we include dynamic and kinematic considerations in any model of skiing I think it is very likely that we won't be very successful.

CalG: In situations of dynamic equilibrium, I feel much better with forces committed to one leg at a time, but in continuous transition between the two.

Fox Hat: David has mentioned in several threads about weight transfer from one ski to the other, and (correct me if I'm wrong, DM), would be more of the opinion that turning involves using the outside ski in the main, whereas I would have thought that using both would be better.

Arcmeister: Good skiing is not as much about being stable as it is about managing instability.
Most of my time skiing is spent falling, the fun is in learning to catch myself as smoothly, and as briefly, as possible.

Tog: I still suspect that DavidM is correct in saying that the body needs a stable platform however brief it is,(and it could be very brief indeed), to function optimally.

DM: Arcmeister really nailed it - “managing instability”. In my opinion the characteristic that most distinguishes the great skiers from the lesser skiers is that the lesser skiers try to cling to stability (or try to find it) whereas the great skiers let go by managing instability. What makes this possible? The great skiers know how to develop a very brief stable platform when they need it and only then. The turn phase between platforms serves as a lead in or preparation for the platform. By letting go of stability a skier can use the external forces to help create a stable platform. If this sounds contradictory I say that it can not work any other way.
Arcmeister: by the time balance zeroes in, it is "then", in the past, history, too late.

DM: I think the reason we are at odds with the two feet/dominant outside foot paradigms is that a basic knowledge of the functional differences of the inside and outside feet may be lacking. Based on input from other threads it seems there is a general recognition that fundamental differences do exist between the outside and inside feet and legs in a turn. I can provide some simple procedures that will help make you aware of what these differences are. This might help to arrive at a consensus on this issue as it relates to platform and rotary mechanics. I will try and post something in the next 24 hours.

Great input on this post. Fox Hat, when we stop learning we are ‘brain dead’.
With reference to the comments of Si and Arcmeister it is my position that to be effective a skier must manage the forces so that the direction of the kinetic flow of the joint system supporting CM that the skier established at initiation is not interrupted by the external forces until the skier allows it to be interrupted.

There seems to agreement with the proposition that we should ski on two feet. The unresolved issue is the manner in which we use our feet and legs (i.e. the lower limb system). I propose that we use the premise of kinetic flow as a basis to discuss how the skier can best use the feet and legs to manage instability while maintaining the consistency of the direction of the kinetic flow of the joint system.
Quote:
 Originally posted by David M:...Based on input from other threads it seems there is a general recognition that fundamental differences do exist between the outside and inside feet and legs in a turn. I can provide some simple procedures that will help make you aware of what these differences are...
DM,
I agree, there are differences, because even if we were to have exactly equal weight on each leg, becuase of the slope of the hill, one would be straighter, while the other is bent, thus how the legs cope with the same weight would be different. Also the differences in the turning (see my comments in the previous thread), that the outside travels further than the inside, and the postscript I added about the perfect pair of skis having different radii on the inside and outside.

Keep the comments going everyone!

S
With reference to the subject of this thread I submit that the following statements are true:

We ski on 2 skis.
The contribution of the outside and inside limbs (feet and legs) varies with the progression of the turn.
DM: Fundamental differences exist in the function of the outside and inside feet and legs in a turn, one of them being that the inside ankle and knee have greater angles of flexion than the outside ankle and knee.
Fox Hat: For balance, you stand over your feet, i.e. the Centre of Gravity needs to be acting over the area of support.
Fox Hat: When skiing the body itself does not move very much relative to the skis.
Si: Unless we include dynamic and kinematic considerations in any model of skiing I think it is very likely that we won't be very successful.
CalG: all dynamic motion is a leap from one position of support to another, in a flow of motion.
Arcmeister: Good skiing …………is about managing instability.

If anyone disagrees with the above would they please post their reasons before we go much further.
Quote:
 Originally posted by Ydnar:John, In the fifth frame Bode has changed his edges for the new turn but he is continuining to move across the hill from the right to the left. He will continue to travel from right to left untill he has used the force generated by the skis to slow and then stop the right to left component of his motion. At that point he can begin to accelerate himself back across the slope from the left to the right. Think of it this way. The first half of what most people would call a right turn is devoted to decelerating the tranverse (across the hill from right to left) component of the skiers motion, the second half is spent accelerating the skier back across the hill from left to right. At that point the skier again changes edges (begins a "left turn") so that he can slow and stop the left to right component of his body's motion. What really blows me away is that I can go from traveling across the hill at 25 mph from right to left to going 25mph from left to right in less than five seconds. Thats like going from 0 to 50 in a car in the same length of time. Hope this makes what I was saying clearer, Yd
Yd,

We agree. We are looking at it from different perspectives. You are saying he is still moving toward the left side of the trail. Absolutely true. I was referring wo what the skis were doing (actually turning to the skier's right).

Yeah, you can probably make that turn in less than 5 seconds, but you need to make sure it's a 180 degree turn, or that your speed over the snow is high enough that you are traveling across the hill at 25 mph.

I had somebody here post the equasion for G forces (a very simple equasion if you take out the fact that we are not of a level surface). It seemed pretty easy to make a turn that produces 1.5+ Gs. There are no cars that you can buy off a dealer's lot that can pull more than about .9 Gs (and they're quite expensive). An F1 car can (I think) pull in excess of 3 Gs, due to the downforces they can create.
DavidM:If anyone disagrees with the {below statements} would they please post their reasons before we go much further

It seems that given the above visual evidence of Bode Miller's movements I don't know how you can say this:
Quote:
 Fox Hat: When skiing the body itself does not move very much relative to the skis.
I mean if you just isolated Bode's body movements in the photo montage and put him in a room doing that position sequence that would be some pretty heavy duty aerobics! Is this not significant movement? What do you need to do for significant movement? Flips?

Quote:
 Fox Hat: For balance, you stand over your feet, i.e. the Centre of Gravity needs to be acting over the area of support.
Perhaps this is the difference between dynamic and static balance? Surely in dynamic balance the COG is not always over the area of support as evidenced in the Miller photo montage. In what frame is his COG over the base of support? In the first frame it's probably inside towards the pole, he probably comes closest in the fourth frame but then at least one and I suspect both skis are off the snow, and his COG is behind the feet.

So by that "definition" he's never in balance.
Tog: It seems that given the above visual evidence of Bode Miller's movements I don't know how you can say this:
Fox Hat: When skiing the body itself does not move very much relative to the skis.

I mean if you just isolated Bode's body movements in the photo montage and put him in a room doing that position sequence that would be some pretty heavy duty aerobics! Is this not significant movement? What do you need to do for significant movement? Flips?
DM: Fox Hat's statement depends on where the forces are acting. Bode or anyone else meeting the effective skier criteria has to "manage the instability". I extrapolate this to mean that to manage instability a skier must also manage the forces and not let the forces manage them. Is Bode doing this? I think so. If so, how is he doing it?

Fox Hat: For balance, you stand over your feet, i.e. the Centre of Gravity needs to be acting over the area of support.

Tog: Perhaps this is the difference between dynamic and static balance? Surely in dynamic balance the COG is not always over the area of support as evidenced in the Miller photo montage.
DM: Do you know that for certain. Maybe Bodes knows something we don't.

Tog: So by that "definition" he's never in balance.

DM: Let me qualify that by adding one more point:
Balance is a reflex response to an external force.

So we agree that sometimes Bode will be out of balance. But he still needs to manage the instability in order to make it possible for him to balance when he needs to.

Agree?
jpfiefer: "Noteworthy also, i think, is that the angle Bode is skiing the edges does not result from an attempt to tip the edges, but rather from leaning into the turn the way he does."

What does that mean? Help me understand. I'm confused and baffled.

Bode's famous for the most direct line on the circuit. He creates edge angles us mere mortals can only shake our head at... to shorten the radius - and you think his edges are at this angle just because he is leaning, not "attempting" to "tip" them on edge? Huh?
Quote:
 Originally posted by Tog:I mean if you just isolated Bode's body movements in the photo montage and put him in a room doing that position sequence that would be some pretty heavy duty aerobics! Is this not significant movement? What do you need to do for significant movement? Flips?
Tog,
Take a look at the montage again. Look at his torso. Take a look at the distance from his arse to the inside ski. From what I can see, it has only moved a couple of inches. If that's heavy duty aerobics, you must be out of shape!

[img]smile.gif[/img]

S
Whygimf,
I try to point out the following, hmm, let me back up:
The extreme angles of many racers are obvious. I've read in a previous thread that poster's tried to achieve angles by tipping the ski. IMHO, that does not go very far - I tried to explain that the angle is not a result of explictly trying to tip the ski, it is a result of leaning into the turn with the lower body. By doing so, the legs angle away from the torso and now the edges are being tipped at basically the same angle.
Hypothesis: Internal stability must be present in order for a skier to manage external instability.

Ergo: Instability can not manage instability.

Agree? Disagree?
Was a crime committed? Was Bode pulled over the edge? Or did he push himself over the edge as he started his new turn.

I submit to you ladies and gentlemen of the epicski jury that if in fact Bode was pulled over the edge then he is guilty of not managing instability. What say you members of the jury?
Wtfh: Look at his torso. Take a look at the distance from his arse to the inside ski. From what I can see, it has only moved a couple of inches. If that's heavy duty aerobics, you must be out of shape!

Fox, in the last frame his arse is maybe 10" off the snow and probably gets down to just a few inches. So it's gone from let's say 30" above the snow down to 3" (Bode is a tall guy). His right arse is probably 15" inside his right foot but his left arse is well over 2 feet inside his left foot.

There's only so much you can move! He couldn't possibly do this in Aerobics class because he'd fall over without the forces pushing him into his feet.

DavidM, I agree with the hypothesis but you've lost me in the court case.
Tog you are trying to compare situations where the forces acting on a body (human) are very different. The forces acting on Bode in the photo sequence are much more complex than the forces in the hypothetical situation you are using to compare him to.

The issue of the crime. Is Bode actively extending his leg(s) as he starts his turn to create a force acting downhill that is:
1. Less than the external forces acting on him that tend to pull him downhill,
2. Equal to the external forces acting on him that tend to pull him downhill, or
3. Greater than the forces acting on him that tend to pull him downhill?

In summary, did Bode jump or was he pushed? In past threads many discounted the role of extension as having no value in initiating a turn.

PS: When I refer to internal stability' I mean dynamic stability. This is required to maintain the kinetic flow of the joint system as a skier moves in space.
DavidM, I was only talking about physical distance that his body moves relating to the assumptions fox made that we only move very little in relation to our feet.

Your court case is a good question. I think Bode is allowing his feet to go way outside and using the force that pulls his body down the hill. So I don't think he "jumped". I see no platform from where he could have "jumped" from plus I see a lot of momentum to his skis shooting out to his left and the outside of the new turn.

You might be interested in this quote I found from Jean Mayer in "Ski Taos Style", 1991 by Jerome Gladysz.

Quote:
 Grounding yourself to the snow is a feet-to-the snow sensitivity. This feeling establishes balance and the ability to work with your own center of gravity. This permits a feedback from the mountain that allows you to know where you are. To ground yourself is to control fore, aft as well as lateral balance. It is finding the sweet spot on the ski, like you would find the sweet spot on a tennis racket or a golf club. The sweet spot makes all the difference in ball performance, it goes farther, faster, and straighter to the target. In skiing, the ski acts and reacts as it should. The sweet spot provides the sensitivity and awareness that is the basis of your center of gravity, sense of balance and transfer of weight. Proper grounding is also the basis of all other body movements. For example, as you come down the slope your vision is normally way out in front of you. Your mind is automatically programming compensations for the terrain that is approaching. The action and reaction of your body movemnts will be illegitimate if your body is not properly connected with the snow or is not effectively grounded. Your mind will make assumptions on what to do, where to go, what pressure to exert based on information that is false. The physical response can only be effective if you are grounded. Most skiers use body movement to affect change of direction in skiing. The problem arises if the physical response is not effectively grounded, it may declare itself as a negative movement. ... Proper grounding allows the independence of leg action and the ability to transfer weight instantaneously.
gotta go...
to Utah!...

[ January 24, 2003, 07:32 AM: Message edited by: Tog ]
Tog,
Not the snow, the SKI. I was talking about the skier and the ski, not the skier and the snow.
Instructors talk about having a quiet upper body, don't have it moving too much, and let the legs do the work. His body, relatively speaking, is hardly moving.
Am I explaining this wrong, or am I just getting the idea wrong?
:

S
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