How does PMTS generate rotary turns like at the top of Mogul

PMTS Forum

Postby mechanic » Tue Apr 06, 2004 10:21 pm

Jeff,

To get a feel for what I mean when I talk about pointing stick your pole in the snow to the left side of your skis and while holding it firmly in place try to push it over with the outside of your left ski. That's the feel of pointing.

For going back and forth from carve to brush I adjust the blend of tipping and pointing. More toward the pointy feel for brushing and more toward the tippy feel for carving. Snow conditions will also affect just how I have to blend the two to achieve the ski snow interaction that I want.

m
mechanic
 

Interesting - how much can one tip

Postby John Mason » Wed Apr 07, 2004 2:21 am

If you tip your foot in it's properlly aligned boot and you have little ankle flexion, you cannot tip very much. But drop yourself down a tad and you can tip a ton. This tipping is visible and can be quite pronounced.

In the transition between turns when flexion is greatest, tipping can be greatest to, which is a good thing, since this helps move the CM down the hill and over the skis.

Also, in a hockey stop with the phantom move, where you are not flexed much at all, the inside leg at the heel is lifted up so their is flexion in that leg and thus it can be tipped. When I do a turn shorter than the carving radius of the skis like a hockey stop, I do this by tipping first. I'm just interested in the mechanics of why this works.

When you tip that knee points into your next turn, but since your tipping as your primary movement, the skis stay parallel.

I was skiing with a nice PSIA guy Monday. He was giving a pointer or two to my Brother in Law who was experiencing his first day of skiing. One of the things he said to my Brother in Law (after he was already skiing parallel and doing easy blues) was to turn right point your knee right.

Luckilly we had already seen this instructor going down a black with consitent divergent tips on each turn. In other words he was indeed using some inside leg steering to effect his turns. He also tipped so I wonder how close this is to what Mechanic is saying as there was blending of both concepts going on.

Anyway, I had already demonstrated to Warren (the first timer) that tipping results in the knee pointing in the direction of the new turn but keeps the skis parallel. It was just interesting how a slight difference in an external cue can have a subtly different result. That's one of the things I like about PMTS is it's definition of terms and the selection of the best external cue for the skiing movement being sought or taught.

I would ask others posting in this thread and mechanic to think about your tipping. How much tipping can you do? Is it visible or just internal to the boot? Once your edging and your lined up with your body in your turn there is not as much externally visible tip. The skis are tipped and edging but your body is lined up with all that tipping. But at the initiation of turns or to generate turns less than the skis natural radius is the tipping observable and not just an internal thing? Certainly in all of the 3 release drills we practice in PMTS, the tipping at release is visible. Easily visible to others. In the weighted release, if your following HH, you see the 2 ski tracks jump the width of the skis as he tips the skis over. But this is in transition before the body has come over the skis. The tipping helps pull the body over. There is a lot of visible tipping of the inside leg when this occurs.

In my case, I know it's observable. I demonstrated it over and over to Warren on his first day of skiing. I also know it can't be done if your standing straight up in your skis or at least not to the extent I'm talking about here. This is easy to play with just standing up. Flex more and you can tip more.

Another possible difference in interpetation, may be, do we tip at the ankle alone? Or, while that occurs, it follows that the whole lower leg tips as that knee points into the next turn? Is that a good clarification point? Obviously if people think that the tipping PMTS is talking about is just within the boot, then there would not be external tipping visible. But I think its the whole lower leg in response to tipping the foot.

And - I'm skiing Friday and Saturday at Nubs Nob if anyone wants to tag along. Best spring skiing in the Midwest and only 25 dollar lift tickets. It's below freezing each night and they still have a 50 to 60 inch base. Look for the grey coats, bright green boots and 6 stars or Head I75m's towards the afternoon.

Anyway - I played with this whole pivot turn with PMTS thing while Warren was practicing and I don't really see any inside leg steering at work there. It seems to be a pivot based on the tipping. I'll have my son video me on some of these moves and post a link for streaming video next week. Maybe I can see what's going on that way.
John Mason
 
Posts: 1050
Joined: Wed Feb 18, 2004 10:52 pm
Location: Lafayette, Indiana, USA

Mechanic

Postby John Mason » Wed Apr 07, 2004 2:32 am

Hi mechanic. That pole exercise sounds like classic leg steering. I had it in my first lesson, but it was all focused on the weighted outside ski. This sounds like you are doing this same steering/pointing but with the inside ski.

Is that what your saying?

I may ultimately convince myself that it is inside leg steering with the tip that creates a pivot turn or hockey stop. The skis stay parallel, but that may just be because the outside ski comes around very easy in these pivoting situations.

The proof of the pudding would be to see in a video if there is divergent tips in the skis or not.

All I know is that when I do a pivot turn with the phantom move, I'm not excerting any conscious steering force on either the inside or the outside leg, but just lifting and tipping the inside leg. The more I tip it, the more the outside flattened ski comes around. Maybe that's the ticket because in this style of turn, I'm not trying to edge. My stance ski is flat so that it can pivot or turn more tightly.

I think Piggymurderer in an earlier post suggested that the external femur rotation occurs if it's not tipped with the inside leg. That's what I feel in my infamous doorway test anyway.
John Mason
 
Posts: 1050
Joined: Wed Feb 18, 2004 10:52 pm
Location: Lafayette, Indiana, USA

Postby Jeff Markham » Wed Apr 07, 2004 6:21 am

mechanic,

Thanks for the elaboration. I think that I understand "pointing" better now.

If I am understanding correctly, you are applying lateral pressure to your free foot's little-toe edge. That would explain why there is no external evidence and no rotation and no diverting of the ski tips.

Am I correct in my understanding?

Given this, here are some more questions:

1. How much weight are you placing on your free foot? I am assuming that some weight is required to "point", even if it's only 5%.

2. As you apply more/less "pointing" are you also increasing/decreasing the weight on the inside ski?

3. At any time, are you supporting your weight with your inside foot? Just curious here...

4. Are you applying lateral pressure along the entire ski length or is it focused more on the front of the ski?

5. When you "point" more, does it decrease brushing or increase it?
Jeff Markham
 
Posts: 87
Joined: Tue Oct 21, 2003 6:53 pm
Location: Sandy, Utah

Postby piggyslayer » Wed Apr 07, 2004 6:50 am

Mechanic wrote:

First for Piggy. What I think you are saying is that to ski that run slowly you must make short turns. Turns shorter than the ski can carve. To accomplish this you pressure the front of the ski untill the tail washes out and skids around shortening the radius of the turn. What I would do would be similar but with a few significant differences. Rather than pressure the front of the ski I would remain centered and use the pointy feel to create the amount of brush that I want to use in that turn to go to the point I want. Because of the way I am creating the brush I feel that I have much more control over it than I would if I made it happen your way. I can turn it on and off at will, I just can't do that if I use your method. Now, a question. On that same slope what if you wanted to make GS type turns at a snails pace? What would you do?


Here is my delayed reply: One small correction (just to be clear) about lateral brushed turns, the brush is not major contributor to speed reduction (it is simply a side-effect). There is just not enough energy that can be dissipated by brushing action of ski tail that does not want to stay in trucks. Do not take me wrong, it will make a difference between winning and loosing a race, but in overall picture this is not major contributor. The curvature of the arc carved by the front of the ski is the main contributor.
Think of a skier doing straight down (no turns) pulling a light sled which brushes his tracks. Magic keeps the sled from bumping up and down and flipping over. He will still go very fast, would he not?

The benefit of such lateral ?semi-?carved turns is that they provide unbelievable control, allowing me to control speed in situations where many other skiers have to rely on their experience in skiing fast (well developed over the years of practice :wink: ).

It is possible to reduce or eliminate the brush (obviously within limits) and create carved turns with radius shorter than factory specified ski turning radius. This has been discussed in other threads. There is, however, a limit how short radius you will get this way and if you go shorter then you will start brushing.

As for snails and GS turns, I think you would not be able to make them either. If you make long radius turns you will go fast no matter how you are shaping the turns (with lateral or rotational forces). True carved turn will be faster, but then short radius lateral brushed turns are likely to be faster as well when compared to similar radius ?rotary?/?pivoting? turns.
Conservation of Energy is a law of physics, not just a guideline. You cannot balance out too much with a rotational torque or your knees will get damaged. What you are describing is more an action to shape the turn (If I understand you correctly) and this will not impact speed reduction dramatically (but will make a difference in GS race).

Mechanic, I am not qualified to comment, criticize you skiing. I have simply explained what works for me. My understanding is that what you are doing is not PMTS, it is an interesting reading though.

John wrote:
I think Piggymurderer in an earlier post suggested that the external femur rotation occurs if it's not tipped with the inside leg. That's what I feel in my infamous doorway test anyway.


John this is plain name calling, how could you! :cry:
My understanding is that femur rotates always when you tip, this is how our bone structure accommodates for the foot inversion (tipping). The point is that if you move you hip in the same direction as you tip (or rather let the hip move were it wants to move) the effect on the stance foot is not rotary, it is lateral. The stance foot will want to tip to the big toe side rather then twist.

Think of this that way: Tipping you free foot is a lateral movement of the foot, still it causes femur of the free leg to rotate. So why would you assume that femur rotation in the stance leg HAS TO result in rotary movement of the stance foot? Obviously it does not, it can result in lateral tipping movement as well.
Piggy Slayer
let the piggy breathe
piggyslayer
 
Posts: 320
Joined: Tue Nov 04, 2003 9:27 pm
Location: New Jersey

Postby -- SCSA » Wed Apr 07, 2004 7:24 am

Free the piggy!
-- SCSA
 

Postby BigE » Wed Apr 07, 2004 10:10 am

piggyslayer wrote:Think of this that way: Tipping you free foot is a lateral movement of the foot, still it causes femur of the free leg to rotate. So why would you assume that femur rotation in the stance leg HAS TO result in rotary movement of the stance foot? Obviously it does not, it can result in lateral tipping movement as well.


May I suggest that the rotation of the femur of the stance leg is purely the result of the stance ski tipping and not it's cause?

If, as the inside ski is tipped onto LTE the inside femur rotates, then as the outside ski is tipped onto BTE, so the outside femur should also rotate. The lateral movement of the hips ensures that the outside ski gets tipped while the outside femur has not yet rotated. In short, all femur rotation happens after the tip of the corresponding leg.

Comments?
BigE
 
Posts: 1519
Joined: Wed Jan 14, 2004 11:42 am
Location: Toronto, Canada

Postby Jeff Markham » Wed Apr 07, 2004 11:12 am

My understanding of PMTS is that the movements are transmitted in a chain.

Tip free foot -> O-frame occurs (i.e., piggy) -> inside femur rotates -> pelvic cradle does *something* and hips move laterally inside turn -> external femur rotates -> stance foot tips.

Am I wrong?
Jeff Markham
 
Posts: 87
Joined: Tue Oct 21, 2003 6:53 pm
Location: Sandy, Utah

Postby mechanic » Wed Apr 07, 2004 4:13 pm

Wish I could type faster. there are a lot of things here that I would like to touch on but my time is short.

To start with the talk about inside leg steering got me curious so when I was skiing today I tried three methods of pointing the inside ski. One was to point the ski by rotating the femer in the hip socket. This produced a strong turn with a definate divergence of the inside ski. When I pointed the foot by pointing the knee into the turn I got a strong turn with some divergence of the inside ski but much less than in the first set of turns. When I pointed the foot by feeling the foot point the result was a strong turn with no divergence and the added benefit that the edge of the inside ski was engaged and that ski is bent and working.

So, because my pointing my foot does not produce divergence is it outside your definition of inside leg steering? Prehapse, we need a new phrase, inside foot steering. Inside foot steering produces divergence only if the ski is lifted off the snow but why would I ever lift the ski off the snow.

Thank you all for your responses. I'll try to respond to everyone but like I said above I type slow.

If any of you are still on snow and could play with the pointing thing and give me a little feed back about how it affects your skiing I would really appreciate it. Ive always wondered if I could communicate this move well enough in words alone for someone to try it and get the results from it that I get or that I can get someone to experience in person on hill.

m
mechanic
 

That's interesting stuff

Postby John Mason » Thu Apr 08, 2004 12:02 am

So you tried 3 ways of turning with the inside foot. There is a fourth way of turning it sounds like you didn't try. What about just tipping the inside foot only without pointing it. If your experience is like mine, this will also turn you without any pointing of the foot at all.

That 4th way is the phantom move taught in PMTS or what Lito describes in his book as phantom edging. Try it carefully with no pointing. Try it with flexion or more upright. Try it weighted in the snow and lifted. Try it with the tip in the snow and the tail raised. You have a good way of explaining things and like to observe and try things. I'd be interested in your feedback.

Lito in his book "Breakthru on the New Skis" on page 89 thru 91 describes Phantom Edging as the way to control the arc and size of a carved turn. He also covers inside and outside leg steering and why these methods can get you into trouble. HH in his books, is more doctrinal in his approach and does not really go into all the pros and cons of the different ways of turning. In that regard I really like Lito's descriptions. But Lito's Phantom Edging and PMTS's phantom move are the same technical movement pattern and does not involve pointing the foot towards the new turn or using steering to shape a turn.

Here is a quote on page 91 as opposed to the idea of leg steering to shape a carved turn: "And I repeat: the secret of shortening up a carved turn is simply to increase your phantom edging. More phantom edging equals a shorter carved turn. Try it"

I should explain Lito's view of a carved turn. He views carved turns as a broad range of turns from what he calls "brushed carves" to "pure carves". He is not talking only about a strict highly edged carved turn here, but a turn resulting from carving movements created by phantom edging. This is a very broad range of turn types just as in PMTS. This is as opposed to turns that skid out the tails or are stemmed in their entry. That's a broader definition of carved than most people use which also is why people think PMTS is a limited approach. That has to do with that "carving" definition.

Lito also has a nice picture sequence illustrating the move and it's not "in the boot" but the tipping is clearly and externally visible. (page 89)

Sorry Piggyslayer about "slaughtering" your nickname. :oops:
John Mason
 
Posts: 1050
Joined: Wed Feb 18, 2004 10:52 pm
Location: Lafayette, Indiana, USA

Postby mechanic » Thu Apr 08, 2004 6:51 am

John,

Prehapse it would be helpful if I gave a little of my background here to put my comments in some kind of context. I have been a ski instructor for 18 years and ski 120+ days per year. I've always been something of a tech head so I have tried just about everything possible to make skis turn. With that bit of info I'll reply to yout post.

I have played a lot over the years with creating turns just by tipping the foot. I can in fact create any turn size, shape or type from pure RR track type carved arcs to the hockey stop type move you have refered to just by tipping the foot. I can also make these same turns just by pointing the foot, and I'm pretty sure that you wouldn't be able to tell which cue I was using to generate the turns. That being said, the RR track type turns are much easier to accomplish using tipping and the hockey stop move is easier with the foot pointing move.

If you are willing to accept the above then it seems to me that either tipping or pointing the foot could be looked on as a primary movement and the question of why the two different cues can produce the same results comes up. Here is my answer to that question. When you tip the foot inside the boot you quickly run out of tipping room in there so as you try to tip further you activate the kenitic chain and begin to use the larger parts of the body to effect tipping. When I point the foot the pointing is restricted by the snow surface so when I try to point more the kenitic chain is activated and I begin to use the larger parts of the body to effect the pointing. In either case the first part of the body to come into play is the knee. The knee appears to move lateraly in response to either cue. But we know that the knee just doesn't flex lateraly so what is happening to give this appearence is rotation of the flexed leg. So tipping results in rotation of the leg and pointing results (a little more directly prehapse) in rotation of the leg. What happens furhter up the chain is largely due to this rotational movement and/or the limiting of that movement. I want to point out that in both cases the rotation of the leg is an outcome of the cue and not the cause of the cue I don't use rotating the leg to point the foot I use pointing the foot to effect rotation in the leg. So, it would seem that as we move further up the chain both cues are going to produce similar results.

I have stated that I use a blend of tipping and pointing in my personal skiing because that blend allows me to ski anywhere making any type of turn I want in the most efficent manner I have yet discovered. I teach both cues to my students because I feel that blending them will give them the best skiing outcome. Also, I teach both because every student is going to respond to the cues differently, for some pointing clicks better than tipping and for others tipping is the feel they can most easily relate to. I can use either cue as a pathway to advancing the student to the level of skiing that they aspire to.

This has been a fairly long post for me so I'm going to take a break then come back for a more direct response to Jeff and to the porcine one.

m
mechanic
 

Tipping and Pointing

Postby John Mason » Thu Apr 08, 2004 8:07 am

Thanks for the clarification M

I reread your post and see that you were exploring the ways of inside leg steering that can be used that may be resulting in the pivot type of effect at the top of a mogul. I misinterpeted what you were saying to think you meant no tipping was occuring.

If you point subtly while tipping the inside leg, but it's not a gross movement and its mixed with tipping that may indeed be what is happening at the top of the mogul. Parallel is maintained but very short turns are possible.

This is very close in description to what I was told was happening by a PMTS instructor. Neither Lito or HH really explain the best actions in their opinion for this short type of pivot turn. It may be that the student just figures out point while tipping or die. In my literal brain must understand first before body will carry it out learning model - I really would like the official explanation.

Eric and Rob in their book Ski the Whole Mountain describe the same phantom move. They also describe how even in a hop turn while your airborne to use the phantom move to turn the skis and position the body for landing. But, are they using the phantom move with pointing in this case? Certainly they are not letting their skis turn them while in mid-air.

I know PMTS eschews some terms because they are so easy for people to misuse and steering or pointing are two of these terms. But obviously in the repretoire of approved PMTS movements and turns these very short turns occur. I just am exploring what is actually happening.

Pointing is an active movement just as steering is. Pointing the inside free ski is very easy to do and the stance leg comes around. Inside leg steering normally creates divergent tips and can be a bad thing.

How does body position and uncoiling address these issues. On the top of the mogul, you pole plant right at the top and then come down the other side with the phantom move. The pole plant makes your body face into the new direction so there is a strong rotational component on both legs to come around to the bodies new direction. The phantom move and the fact you are at the top of the mogul make you come around. Is it anathama to PMTS to point that inside foot into the new direction?

If and when is any type of inside leg steering recommended in conjunction with PMTS. This is the specific question I'd like to see addressed. If in a PMTS viewpoint no steering occurs then what is happening with these very short turns.

M - for all I know I'm pointing like you are describing. I don't feel like I am but as you say, the move is subtle and produces a big result. So I might be.
John Mason
 
Posts: 1050
Joined: Wed Feb 18, 2004 10:52 pm
Location: Lafayette, Indiana, USA

Postby mechanic » Thu Apr 08, 2004 10:04 am

John,

You may not realize it but you have came across a very important fact about all this stuff. Tipping and pointing are just opposite ends of the spectrum of one of the ways we move our feet. You can't tip without there being a rotary component involved and you can't point without there being an element of tipping involved. So you are indeed pointing but you have never been aware of it because you have never been made aware of it. Further, the harder, faster, more you tip the greater rotary component you introduce. this explains for me why you can get a rotary move like a hockey stop while focusing on what you had thought of as a purely edging move. On the other side of this interrelationship if I can't point without there being some edging component involved it explains how I can create RR track turns while focusing just on pointing.

PMTS because of its insistance on allowing no active rotary component in its primary move seems to always be teaching and using techniques that will introduce rotary components into the turn such as the wind-up and release idea you mentioned. Personallly, if some kind of rotary input is required for a turn I want to introduce it in a way that will allow me the most precise control over the input that I can have and up till now pointing has been the way to do that.

m
mechanic
 

Postby piggyslayer » Fri Apr 09, 2004 8:30 am

Reading these posts again, I want to clarify some terms, which may be confusing to readers.

When we say lateral we do not mean any hip abduction/adduction movements, there is no side-to-side movement of the foot (like in moving from wide stance to narrow stance and back). Rather we mean tipping, rolling into an edge.

Word lateral is used to differentiate from rotation which implies rotation in the transverse plane (horizontal plane) - rotating the ski length.

The term lateral is also used to describe ski boot which is designed to transfer lateral rolling to an edge movements well.

Tipping movement is an example of such lateral movement, and there is an ongoing dispute (which I hope will settle now) if such movement can contribute to rotary effect on the stance foot due to the biomechanical phenomena in which free foot movement influences the stance foot.

Just a clarification, maybe not needed.
Someone can correct me if this post is not sufficiently clear.
If my posts confused anybody, sorry.
Piggy Slayer
let the piggy breathe
piggyslayer
 
Posts: 320
Joined: Tue Nov 04, 2003 9:27 pm
Location: New Jersey

Please see newer PMTS post

Postby John Mason » Fri Apr 09, 2004 9:55 pm

My premise for my original question was based on a false assumption on my part that a rotary or pivot action is required to ski bumps. This bad and not required method to ski bumps has been answered.

Please check out the newer PMTS post Harold started. I believe I was needlessly introducing inside leg steering at the top of a mogul due to my own misunderstanding of the best way to do a mogul.

I was playing with lots of things today on the slope and realize its all lateral which results in rotary as you ride the skis. If your getting a strong rotation or pivoting action, then it's probably slight inside leg steering. Tipping of the free foot is more than enough to control arcs. No steering of either inside or outside leg is required.

In the newer PMTS thread Harold started I talk about this more and have a link to a PMTS bump site with video that should help. I believe I was confusing myself with my doorway test. I was not able to duplicate any stance leg steering forces from tipping the free foot in my real life tests on the slope. But I had a whole lot of fun just riding my skis around!

I believe I have had some inside leg steering for some time mixed with what I was learning with PMTS. It's not needed. Its easier to simply drop it. But like any habit you may not realize you are doing it and have to become aware to stop. It's just tipping for me!
John Mason
 
Posts: 1050
Joined: Wed Feb 18, 2004 10:52 pm
Location: Lafayette, Indiana, USA

PreviousNext

Return to Primary Movements Teaching System

Who is online

Users browsing this forum: No registered users and 1 guest