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Where do you stand?

post #1 of 27
Thread Starter 
In the "weight on inside ski" thread, FastMan suggested we start a spur to explore principles of balance and performance as related to the function of the foot.

I'll start with a basic dispute: the reference point of the foot for a good stance. Some say we should center our weight on the heel, for that is where the tibia-fibula intersect with the foot at the ankle and where our weight acts on the arch. Another group says the arch is the critical reference for a good stance, because the arch distributes pressure to the balance triangle (with points at the heel, 1st and 5th metatarsals). A third group says that the first metatarsal is where we want to focus pressure for skiing performance and balance.

Where do you stand?
post #2 of 27
Nolo, you forgot another balance point. The shin to boot tongue contact point. The shin contact point can change the pressure distribution under the foot drastically. Since this is so, I guess I am like a bar of soap on this one. Press me for a solid answer and I am apt to squeeze out from under the answer for the next person. Perhaps I should run for political office.

In general you are right about how we humans balance but in practice, the feel of pressure distribution/balance for every skier is different and I try to get each individual skier to tune into their individual needs.

The main point here is for each individual to find where their weight distribution is when they are over the sweet spot. Just ask a women who has her bindings mounted to far to the rear where her weight/balance distribution is. She may not even be able to find balance when she initiates a turn. it. It takes a good coach watching how you are moving and pressuring the skis to help you sort out equipement problems and find the correct feel and balance points.

In my case, I am on butter soft telemark skis with the bindings mounted forward so that I am right over the sweet spot when I feel equal pressure under the whole foot. I need very little forward motion to get the tips to seek the fall line and very little aft movement to engage the tails. I use rotary tip engagement instead of leverageing to hook the tips up sooner. On a scale of 1 to 10 on tongue pressure. 10 being the highest, the pressure on my shins is always 1-2.

From this position, I am feeling the balance on the heel, arch, first and fifth metatarsals.
post #3 of 27
I start on my arch then to the big toe metatarsal on one foot and my little toe metatarsal on the other foot and end up on my heels or there abouts at the end and then I move forward toward the direction of the next turn and start over again.

The only time I am standing or weighting or pressuring any one part of my foot is when I am standing still and even then I begin to fidget in my shoes.
post #4 of 27
Quote:
Originally posted by Pierre:
In general you are right about how we humans balance but in practice, the feel of pressure distribution/balance for every skier is different and I try to get each individual skier to tune into their individual needs.
This says it for me. If we're discussing biophysical matters, we might be able to develop some answers. However, if we're discussing ski instruction, relating these "biophysical truths" to the student may not compute for that student. It's our task to analyze the student's movements and balance and then decide how we wish to affect it through direction and practice exercises.
post #5 of 27
Great jungle to be explored Nolo!

We probably each have a different optimum "home" posture based on our body type, our fit/mis-fit with our boots, and the net of that fit/mis-fitting with our binding set up relative to our ski's design. And all this is even before we start sliding and turning and add the lateral and acceleration/de-acceleration energy factors.

What all this points to is an amazing adaptibility of the human body to dance in balance with the variables we encounter in skiing.

I watch some skiers with a wide range of fore/aft postures from which they can function "in balance", and others struggling from way out to barely there.

I think boots are the most important variable in the equation.

They are the handle we hold our skis with, and they need to work for our personal grip.

I've been experimenting with using a couple scales to measure for/aft weight distribution, both only with boots and again binding/ski varaibles in the equation. From a relatively small sampling thus far, it is clear that people are all over the map.

From fore/aft of 80/20 to 30/70 in boots, and more different ranges with skis on.

What is optimum? I know what works for me, but hesitate to ballpark others there, given the variables involved.

I think it is important to help each student become aware that good balance should not be that hard. If it is, something probably should be adjusted to make it easier. There may very well be more people in the wrong boots for their needs than those in the right ones. When the boots are not working for you, they are working against you, plain and simple. In a mis-match scenario everything we do is a compensating movement. How skewed is the movement analysis for that skier?

We all wany to demo skis, but I think boots would be the more important comparitive experience to optimize your fore/aft alignment.

If you have a friend with the same size boots, don't trade skis for a couple runs, trade boots!
Without even factoring lateral alignment, the stance should make balancing easier or harder.


For all the strides in the 'science' of lateral alignment for/aft alignment is pretty much hit for most skiers.
post #6 of 27
Quote:
Originally posted by Arcmeister:
I think boots are the most important variable in the equation.

The[y] are the handle we hold our skis with, and the[y] need to work for our personal grip. . .

We all wany to demo skis, but I think boots would be the more important comparitive experience to optimize your fore/aft alignment.
That's been my own personal experience, Arcmeister and I think you hit the nail on the head. I only quoted a part of your post, but the entire post is terrific - thank you!
post #7 of 27
Quote:
Originally posted by Arcmeister:
I think boots are the most important variable in the equation.
Please allow me to jump in here in a recent personal observation even though I am not an instructor in the usual sense of the word. I recently swapped my pair of Nordica boots for some Technicas. While both pairs of boots have been painstakingly fitted by the area's best, the difference in feel has been dramatic especially in the fore-aft weight distribution. In my old Nordicas, in order to apply correct pressuring, I needed to focus on the 1st metatarsal(sp?). In my newer Technicas, I find I am most balanced focusing the feel on my arch. The difference in feel/sensory feedback is most dramatic.

So what I am trying to say is that if
this discussion had taken place a few weeks earlier, I would have strongly identified with the metatarsal group. Today in my new Technicas, I tend to identify with the arch group. Who knows, if I get a third pair of boots, I might be able to identify more with the subtle shin/tongue and heel group represented by Pierre?

I think the important point is that an individual is balanced. The most applicable sensory feedback mechanism to achieve this balance (via sensing metatarsal, arch, heel, shin, or whevever else) depends very much on the individual anatomy and his equipment.
post #8 of 27
Thread Starter 
Is the role of the foot different in a ski boot than in other footgear? Are we asking the feet to do anything different in skiing than in other walks of life?
post #9 of 27
My point was that skiing is dynamic and though we start out balanced on a comfortable spot, we move constantly not only to maintain balance but also to shape turns. I stand on my feet but I move on my skis. My feet and ankles are the fulcrum and my body is somewhat of a pendulum that swings both fore and aft and side to side. We all know this yet we are compelled to state a case in favor of this stance or that. Ideally we are balanced, weighted over the entire foot but that should not last for long. The dance of balance will be determined by our turn shape, our speed, our tatics or intent and our equipment. I seek a stance that enables me to move on my skis in any direction I want.

As you can see by the time of my post that I am cyberskiing instead of the real thing. Darn weather forecast called for increasing clouds and rain. Of course there is not a cloud in the sky and somebody else will be picking all the corn. :

Edit: I've been brewing this post for awhile and just got back to read nolo's post. Just an aside nolo, I've been thinking alot about walking this season. [img]graemlins/thumbsup.gif[/img]
post #10 of 27
Nolo said:
Quote:
Is the role of the foot different in a ski boot than in other footgear? Are we asking the feet to do anything different in skiing than in other walks of life?
Maybe you should ask this the other way around. Do our ski boots allow us to do things differently than walking in our regular shoes. The answer is that our ski boots allow us to do things much more inefficiently and get away with it than our regular shoes would allow.

I think the more we reconcile the differences between the way our feet work in shoes and in ski boots the more balanced and better we ski. I have tried to do this as much as possible and I love the difference.
post #11 of 27
Quote:
Originally posted by nolo:
Is the role of the foot different in a ski boot than in other footgear? Are we asking the feet to do anything different in skiing than in other walks of life?
As I understand the roles by those who really understand foot function, yes. An orthotic for running (shock absorption and energy transmission as the foot moves from impact thru propulsion), is made to serve the foot differently than one made for skiing (stability and support in a more consistant posture, with controlled adaptation).

In skiing we use our feet to manipulate a tool (that is an extension of the foot) using an interface (the boot) that needs to provide support leverage, yet accomidate an effective range of motion for the foot to work to provide balance and intended input to the ski (thru the boot).

I think boots are where the opportunities lie for the next technology growth. Current designs are pretty much based off old design theory for long, straight skis, and technique, with moderate accomidation to enable contempory skiing movements as applied to shape skis.

I see even more advanced skiers than in the past in boots that are too stiff, and low-intermediate boots are still more optimized for walking comfort, than for learning to ski better.

At 200+# I ski a boot a couple models below the race model, and still have softened it even more to provide the range of ankle motion I desire for the skiing I aspire to. I prefer to balance using my skeleton, thru the bottom of my feet, as opposed to levering/leaning on the stiffness of my boots. To some degree ankle flex equates to agility, and I'm looking for all the help I can get.
[img]tongue.gif[/img]
post #12 of 27
Quote:
Originally posted by nolo:
Is the role of the foot different in a ski boot than in other footgear? Are we asking the feet to do anything different in skiing than in other walks of life?
This has only been replied to in two different ways. It screams for a third. Short answer yes.
Walking or running the primary function of the foot is alternately absorption and then propulsion.
In skiing our primary propusion is gravity and absorption is minimized through equipment and snow but most importantly the slope dispersing impact into forward momentum.
On the other hand in skiing the foot has to deal and work with the forces genetated by 1.5+ metres of steel and fibreglass strapped to the foot. It is these forces that also prompt us to encase our lower leg and foot in plastic.

The ankle and foot being supported in it's strongest position is still essential inside the boot given the amount of forces in question. Other footwear requires the ankle/foot to operate with some absorption ability (pronation) the ability to adapt to terrain and lots of dorsi and plantar flexion to achieve propulsion.
post #13 of 27
Originally posted by nolo:
Is the role of the foot different in a ski boot than in other footgear? Are we asking the feet to do anything different in skiing than in other walks of life?
________________________________

I’m really drawn to this sentence in Hannaford’s book “Smart Moves”, “Successful movement requires secure balance, which depends on a sophisticated proprioceptive system constantly aligning every part of the body.

So where is every part of the body aligning too? What's the focus of the alignment? Whether we talk about gravity, disturbing forces, or just standing still, it seems to me we are still talking about aligning to our base of support, our feet. Does it really matter what foot wear we have on? If I'm running walking, or skiing there is always a point when the foot is loaded and the hips are over the instep, and the Center of Mass is aligned over the foot in a functional way so the body is getting the feedback it needs to make successful movements. So I'm gonna put say that our feet always need to work the same, otherwise our body won't know it's in balance. the only difference between skiing and running/walking is the factor of forward propulsion as I see it. Moving from a flat foot up ontoi the ball amd toes of the foot is a move to propell us forward, which is not a balancing move, but I would venture that we can't make that move without first being balanced over a flat stable foot at some point in our stride. In skiing we have gravity to move us forward we don't need to stride, but we still need to have our balance focused on the same flat stable foot.

So I'l take the liberty to change Hannaford's qoute to Successful skiing movements require stable dynamic balance, and I'll say that I feel in this regard our foot needs to opperate in the same manner it does in every other activity we do. Our body is hard wired and built for this, how could we expect it to work differently for one sport? We still need that stable platform in our ski boots. The same one we stride up off of when we are walking or running. I think it's unrealistic to expect our body to rewire/rebuild itself for skiing. Thoughts?
post #14 of 27
RicB wrote:

'We still need that stable platform in our ski boots. The same one we stride up off of when we are walking or running.'

But as you have pointed out the movement is different and doesn't require the propulsion off the forefoot. Further, the boot is a necessary compromise to allow us to handle the leverage of a 150cm foot, particulaly laterally. This stability requirement may use a part of normal 'hardwiring' and is provided by the ankle which has to remain strong throughout, unlike a running step which doesn't have the sideways tip to the same extent.

So we use part of what we are wired with for walking, particularly the rhythm, but with the important difference in the way the ankle is used to allow the needed inclination/ rolling of the foot.
post #15 of 27
Thread Starter 
I would offer that it's not walking per se that's similar between regular ambulation and skiing, but the loading/unloading of the feet. I can prove this by contrasting dynamic shuffle step turns or 1000 steps and parallel turns. Stepping (or any sequential movement) is not stressed in contemporary skiing, which is more about flow and connection, more about transition rather than starts and finishes. In terms of flow, connection, and transition, how I load and unload my feet is critical. As Ric says according to my paraphrasing, this must be harmonious with what I'm already doing anyway, or it will never work in a timely fashion. In other words, my proprioception does not have a bunch of different channels: press 2 for tennis, 3 for skiing, 4 for hiphop, and 5 for waltz. I see everything I do as cross-training for everything else I do.
post #16 of 27
We don't use the propulsion part of the stride, but I believe we do use the same loaded foot balanced stance that our foot moves onto and then past when walking. I would venture if we didn't find that balanced stance in the middle of our walking stride we wouldn't get to far. What I'm saying is that our stance needs to remain in that balanced stance to effectively ski. There is a range of motion in our stance, and when we move outside of that range, our balance system doesn't get the feedback it needs to funtion "effectively". I call that a centered stance, and I think it keys off of the center of mass moving within a certain range over the foot.

What else is the body doing when it is aligning it's parts to effect stable balance. It's aligning the body over a loaded foot. Whether it's aligning to gravity standing still or aligning t ofind equilibrium between the forces in skiing, it's still seeking to find a stable base of support under our foot/feet. Should or could it be doing something different when we ski?
post #17 of 27
Sorry Nolo, this party was my idea, and I arrive late. Very good comments so far, I see much I agree with. For what it’s worth I’ll throw my nickels worth in.

To me, at the heart of the discussion is how we define and recognize the state of being in balance. Skiing involves something called dynamic balance. In contrast to static balance where forces are constant and balance is the relatively simple act of counteracting those non-changing forces, skiing throws a greater challenge at us. In skiing, forces are continually changing and we must make rapid and continuous body position modifications to maintain force equilibrium.

Now here is where the water gets murky. Balance can have many faces. As long as a skier finds a way to not fall over while descending a slope he/she has successfully achieved a state of balance. But as we all know, some of those pictures of balance are more attractive and efficient than others!

So to me the question becomes what defines EFFICIENT states of balance. My philosophy is that the most efficient state of balance is that which is achieved through the natural function of the foot.

The human foot is designed to keep the human body, which is very tall and teetery, from tipping over and injuring itself. In other words it’s designed to provide balance. Common sense, right? My thinking is if we possess such a magnificent bio mechanism, and there is a way to utilize it efficiently in skiing, then it’s something we should seriously explore.

I believe potential to use the foot as an efficient mechanism of balance does exist in skiing. However, to do so one must understand how it functions so that it’s full potential can be milked, and so we don’t do anything from a technical or equipment standpoint that may limit the foots ability perform it’s magic.

So how does the foot do such a wondrous job of providing balance? The foot has within it three separate arches. One from heel to 1st metatarsal (big toe ball of the foot), one from the heel to the 5th metatarsal (little toe ball of the foot), and one from the 1st MT to the 5th MT. When weight is properly applied to the foot those three arches compress, and as they do tension develops. That tension is what provides the stability for balance.

For that tension to develop fully weight must be directed to the foot so that all three points (heel, 1st MT, 5th MT) are pressured. This means our center of pressure must be somewhere mid foot. As soon as pressure moves to far forward or back one or more points of pressure are lost, tension in the arch dissipates, and balance in the foot is compromised.

Also, for tensioning to occur the foot must be physically able to compress and expand, both fore/aft and laterally. This is one situation where equipment comes into play. Boots that are to narrow or short don’t provide enough room for expansion and restrict the arch’s ability to properly tension. And, foot beds that are over arched don’t allow space to compress so the arches remain relaxed and the foot just rocks over the top of the middle of the too high foot bed.

Enough for now, thanks for indulging me. I’ll try to get back later to talk about other factors that compromise foot function such as cuff leveraging, ramp angle, and forward lean. Also I’ll touch on how we can use the natural function of the foot in a way that specifically enhances ski performance.
post #18 of 27
Fastman, that was excellent.

I don't know anything at all about the mechanics of how feet work, but what you wrote just "feels" correct. I can play around with pressuring my foot on the floor and it seems right. Thank you.

One question, however. You mention that too short/too narrow boots take away much of the natural balance ability of the foot. That seems intuitively correct, but then I think about all the stories of World Cup racers whose boots are so tight they can barely put them on their feet. Nevertheless, those racers seem to have unbelievable balance.

Do you think it's that the fit is so good that the balancing flex is still possible even though the boots are incredibly rigid?

I'm just wondering because my impression has always been that their feet are so clamped in that they couldn't move them if they wanted to.

As to my own "where do you stand?", I can tell I'm pretty well balanced when I'm skiing my randonnee boots (pretty soft Scarpa Lasers) and completely forget that I'm on a boot with almost no leverage fore and aft. That sweet spot on my foot seems to be about an inch back and about a half inch outside my first metatarsal. How's that for being specific?

And I tend to be *in* that sweet spot about 4.38% of the time.

Bob
post #19 of 27
Thread Starter 
Another fine post, FastMan. I look forward to reading more about setting the boots up to support and not inhibit the foot's natural function.
post #20 of 27
Balancing is a dynamic process that consists of adjusting or COM in relation to the three pressure points in our feet as the situation requires. Even standing still there will be a constant subtle ajustment. While going through a process like skiing where so many forces act on our bodies it seems unlikely that we will get by using on preferred balance point. Not to forget that diffferent parts of the turn require pressuring different parts of the feet.
post #21 of 27
Fastman that pretty much sums up where I am at. You will know when you have achieved that kind of balance by unbuckling you're boots. If nothing changes except the fact that you cannot be as agressive, you are pretty close in my opinion.
post #22 of 27
Quote:
Originally posted by Pierre:
Nolo, you forgot another balance point. The shin to boot tongue contact point. The shin contact point can change the pressure distribution under the foot drastically. Since this is so, I guess I am like a bar of soap on this one. Press me for a solid answer and I am apt to squeeze out from under the answer for the next person. Perhaps I should run for political office.
Hola Pierre

Good info in that post, as usual, but the reason I quote and highlight the entry is that I think it's a mistake to consider the shin/boot as a balance point. As a contact point I certainly agree it is an indicator of whether we are in balance or not, but the real story on balance is the relation between body mass and feet.

One reason I believe this is that boots, having all sorts of different ramp/cuff etc. etc. angles can really change how contacting the front or back of the boot affects our balance. Ideally if we move to the heel, the back of the leg contacts the rear of the boot evenly from heel to calf precisely at the same time as weight actually reaches the heel. For a lot of people this isn't true, the calf often hits before the balance point reaches the heel, causing a lever action which pushes the foot forward, further out from under the skier.

The same scenario can apply to tongue contact, or an opposite one, in which the balance point reaches the ball, or metatarsals before the shin contacts the boot, making it truly difficult for the skier to ever connect the boot/shin at all unless they move so far forward as to be out of balance.

errr... hope this isn't a pirating move on the boot issues, boot setup and balance pont are exceedingly related.

For my part, I think the balance point can change given conditions etc. Basically I shoot for a ski from the bottom of the foot feel instead of from the cuff of the boot feel.

And when I choose to ski with a little feel for the back of the arch (hesitate to say heel) It doesn't happen by moving 'back to the heel, but by changing the rate of travel and path of the "center of mass".... changing the rate of forward movement so the cm isn't so much ahead of the feet as over them, or maybe directing it a little more laterally than forward which allows the feet/skis to almost get ahead.

To narrow it down as much as possible. I like an even feel over the soles of my feet which allows me the option to select or move to different parts of my feet for different situations/turn shapes etc.
post #23 of 27
Pierre

I agree.

Unbuckle the boots and ski the ski! As a kid, we did the same with our hockey skates to gain a sense of being "planted". One's balance and stance are well revealed when the ankle constraint is taken out of the picture.

I view the motions of skiing as an extrapolation of walking.
For myself, an "aggressive" skiing stance for challenging terrain is very forward . "On my toes". As is the case for all athletic activities. (except perhaps equestrian

As I stand tall and relax on comfortable cruisers, the center of pressure moves back. When I become very relaxed, I'm in the back seat faster than you can say "what the ...."

If I assign a numeric value for pressure balance within a properly buckled boot. 10 as a heel lift condition, and 1 for a toe lift condition, an average pressure value greater than 6 get's my best skiing.

Regards

CalG
post #24 of 27
Thread Starter 
Great post, Roto.

Basically I shoot for a ski from the bottom of the foot feel instead of from the cuff of the boot feel.
post #25 of 27
Roto said:
Quote:
Good info in that post, as usual, but the reason I quote and highlight the entry is that I think it's a mistake to consider the shin/boot as a balance point. As a contact point I certainly agree it is an indicator of whether we are in balance or not, but the real story on balance is the relation between body mass and feet.
Yes and no. For most skiers yes but most skiers don't have very active lateral ankle activity. If you have a lot of lateral ankle activity. That is, if you actively tip the ankles then you do not have three good contact points on the bottom of you're feet. The exception to this is when the feet are under G loading where the forces overcome any lateral ankle ability (forced pronation).

If you have lateral ankle activity, you will have two good contact points and one weak contact point on the bottom of you're foot. In my opinion, you share balance between the weak contact point and the shin contact point to make a strong contact point out of two weak ones through a fulcrum effect.

I get a different perspective on things in alpine mode on a telemark setup.
post #26 of 27
Hmm

The 3 contact point deal is something I will have to pay some attention to before I understand it. I may need some more info as well. To 'boot' it seems to me that people with lots of ankle activity, both fore/aft and lateral tend to ski more from the foot than the cuff of the boot.

One thing I do 'get' is the different perspective from tele gear... though for me skiing alpine on tele gear... learning to carve, pressure and shape long, short and medium radius alpine turns on hard snow while skiing on leather tele boots (it was a couple years ago...) was one of the primary motivators toward skiing from the bottom of the feet as opposed to the cuff of the boots for me.

What I feel is this... if I use cuff of the boot as an actual balance point it takes me longer than a moment to move off of it and back to my feet in order to prepare for, or react to changes of any kind. And move off it and back to my feet is something I must do to effect any changes in my movement patters

What I see is this... skiers who use the cuff of the boot as a contact point usually have a one-dimensional set of movements and have trouble changing what they do for changing situations

My instinct at this point is to 'point' out that if a contact point high on the boot is NEEDED for balance, then there is something wrong with the skier's stance, and possibly the alignment of that particular boot to that particular skier.

But hey, it's all about learning and I am intereseted in your references to 3 contact points. Esp. the weak vs. strong ones. It seems to me there is an oppoprtunity for both of us to learn by exploring the ideas there.
post #27 of 27
Roto, I don't think you are looking at it from my perspective. If I lean on the fronts of the boots, it will take more than a small amount of time to change that. I need to stand back up from a fall first.

It takes little contact to affect a large change because the boot tongue is not in the same plane as the other three contact points. If I unbuckle my tele boots, I am skiing on the footbed period. The cuff on a Crispi offers nothing unbuckled.

The change I see is that the range of motion that I have to balance within is greatly reduced. I must keep more weight on the third contact point instead of dividing the balance between the cuff and the third point.

What I am saying is that I don't have to have much pressure on the boot tongue from my shin in order to let me roll the ankle laterally and take some pressure off one of the contact points. For example, on the new inside ski, this would allow me to lift the 1st metatarsal a bit inside the boot. I guess what I am saying is that I can be more agressive in movements.
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