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Perception vs. Reality: Ski Tracks; What is really happening? - Page 2

post #31 of 131
Thread Starter 

A Few Points:

A few points for discussion:
  1. The Phantom Move (or whatever you want to call it), by its very nature uses inside ski redirection [rotary] at the very top of the turn in order to make the ski paths divergent. In a non-exaggerated turn this is so minimal that you can almost discard its existence (which has been done in PMTS) but the fact remains that the movement exists.
  2. The Phantom Move also puts the inside ski on a track that closely resembles the outside ski so that no further redirection has to occur after the point at which the move is executed.
  3. In a PSIA style turn where the inside ski is tracking a different radius from the outside ski (much smaller), the inside ski must constantly be redirected by using rotary or awkwardly tipped onto a higher edge angle than the outside ski.
While the tracks that have equal separation on the snow may look more pleasing to the eye making a turn that requires the inside ski to be redirected through the entire turn is not exactly what I would describe as an efficient movement (hence my reference to efficiency).

Now, someone brought skifex and her turns into the discussion. I would argue that he turns and her type of skiing do not completely fit the models that we are looking at... especially when you take the CM movement into consideration. [The only way that she can maintain weight on the outside ski with her skiing is due to centrifugal and centripetal forces between her skis and the snow and the snow to her skis as her CM is falling way inside of the turn. However... if you take ONLY her lower body into consideration you will notice a sequence that resembles the 'real world' tracks that I drew in the original drawing. If you look closely you can even see a move that lends itself to pulling back the inside ski...]

Later

GREG
post #32 of 131
Quote:
Originally Posted by HeluvaSkier
A few points for discussion:
  1. The Phantom Move (or whatever you want to call it), by its very nature uses inside ski redirection [rotary] at the very top of the turn in order to make the ski paths divergent. In a non-exaggerated turn this is so minimal that you can almost discard its existence (which has been done in PMTS) but the fact remains that the movement exists.
  2. The Phantom Move also puts the inside ski on a track that closely resembles the outside ski so that no further redirection has to occur after the point at which the move is executed.
  3. In a PSIA style turn where the inside ski is tracking a different radius from the outside ski (much smaller), the inside ski must constantly be redirected by using rotary or awkwardly tipped onto a higher edge angle than the outside ski.
While the tracks that have equal separation on the snow may look more pleasing to the eye making a turn that requires the inside ski to be redirected through the entire turn is not exactly what I would describe as an efficient movement (hence my reference to efficiency).

Now, someone brought skifex and her turns into the discussion. I would argue that he turns and her type of skiing do not completely fit the models that we are looking at... especially when you take the CM movement into consideration. [The only way that she can maintain weight on the outside ski with her skiing is due to centrifugal and centripetal forces between her skis and the snow and the snow to her skis as her CM is falling way inside of the turn. However... if you take ONLY her lower body into consideration you will notice a sequence that resembles the 'real world' tracks that I drew in the original drawing. If you look closely you can even see a move that lends itself to pulling back the inside ski...]

Later

GREG
Seem t ome we are making alot of assumptions here.

#1, I don't know that the skis diverge from rotary, from the leg getting shorter, or from both happening at the same time, or other issues. Dynamicly pull the inside heel towards the butt, and you will get diverging skis, but you can also get there by simply unweighting the inside ski, countering too much and steering the ski along it's way.

I've never been in a pmts clinic, so I don't know how this would work out other than to say I have read book two, and played with the concepts.

#2, "Closely resembles" will still require some redirection or "guidance" in my view. The only way to get to no further redirection needed would be to have them in the same exact track and radius. As they say, close only works in horseshoes.

#3 What is phantom to me is that proverbial "PSIA turn". What is it? Aren't the skis always tracking a different radius? I mean, we talk of parallel tracking of the skis, but doesn't this require some guidance and redirecting whether it is a " pmts turn, or a psia turn"? Does parallel really even exist if the skis aren't are not tracking the same radius? I see the same thing happening with regards to the continual guidance of the skis in both of your types of turns that you want to draw a distiction too. The bias may differ between priorities, tipping versus guiding to keep a consistent width, but both require some guiding because neither have the same radius happening between the inside ski and the outside ski.

Skifex's skiing inefficient? Perhaps, but we would really have to scientifically evaluate the tension and btu's happening in the body to really determine this. Is angulation always more efficient than banking in terms of muscle energy expended? To me she looks realxed, fluid, and playfull. I've watched Nick Herrin skiing vey similar to this when he was being "playfull". Well those are my thoughts. later, RicB.
post #33 of 131
Thread Starter 
Quote:
Originally Posted by RicB
Seem t ome we are making alot of assumptions here.

#1, I don't know that the skis diverge from rotary, from the leg getting shorter, or from both happening at the same time, or other issues. Dynamicly pull the inside heel towards the butt, and you will get diverging skis, but you can also get there by simply unweighting the inside ski, countering too much and steering the ski along it's way.

I've never been in a pmts clinic, so I don't know how this would work out other than to say I have read book two, and played with the concepts.
Here is the thing with this: The inside ski must undergo rotary if you are making a 'RR track' turn. If you unweight it, lift it, or anything else, while keeping it parallel with the outside ski you do not get a smooth track - you get something that looks like the tracks when someone is skiing with too much tip lead and scissoring. For the record I have never been to a pmts clinic either. I simply used the model for the turn because that is a similar turn to what they teach in that particular system... it is also VERY close to a slalom race turn.

Quote:
Originally Posted by RicB
#2, "Closely resembles" will still require some redirection or "guidance" in my view. The only way to get to no further redirection needed would be to have them in the same exact track and radius. As they say, close only works in horseshoes.

#3 What is phantom to me is that proverbial "PSIA turn". What is it? Aren't the skis always tracking a different radius? I mean, we talk of parallel tracking of the skis, but doesn't this require some guidance and redirecting whether it is a " pmts turn, or a psia turn"? Does parallel really even exist if the skis aren't are not tracking the same radius? I see the same thing happening with regards to the continual guidance of the skis in both of your types of turns that you want to draw a distiction too. The bias may differ between priorities, tipping versus guiding to keep a consistent width, but both require some guiding because neither have the same radius happening between the inside ski and the outside ski.
The PSIA model that I am referring to is those who tout constant track width as a focus of skiing. We are also talking about radii that have only a difference by a few centimeters here (for a turn with diverging/converging tracks). The big thing to note here is - how does this outcome compare to purposely making the inside ski track a smaller radius as with the constant track width turn? The movements that you will make for each turn are significantly different. In the divergent/convergent track turn you make one movement at the top of the turn, versus a series of movements or a constant movement through the entire turn to direct the inside ski. Also, what is happening to the horizontal component in each turn and how is it effecting where the path of the CM is (assuming either a banked or countered turn, preferably both)?

Quote:
Originally Posted by RicB
Skifex's skiing inefficient? Perhaps, but we would really have to scientifically evaluate the tension and btu's happening in the body to really determine this. Is angulation always more efficient than banking in terms of muscle energy expended? To me she looks realxed, fluid, and playfull. I've watched Nick Herrin skiing vey similar to this when he was being "playfull". Well those are my thoughts. later, RicB.
You will note that I did not comment on the efficiency of the skiing that SkiFex does in her clip. I only stated that the upper body movement does not really fit what we are discussing... However, I did note that if you isolate the lower body you may see a bit of what we are discussing here... but it will not likely translate into a good example when CM is taken into consideration.

Later

GREG
post #34 of 131
Thread Starter 
By the way, my original persuit into this topic came after working on my own skiing this last season, and seeing how a focus on track width, or horizontal width in the transition adversely effected my own skiing (as most probably recall from watching my own skiing). It made me rethink my goal for my turns considerably. The difference was noticable toward the end of the season (unfortunately no video of that).
Later
GREG
post #35 of 131
If you're talking about PMTS and "rotary" you have to know that Harald's definition of "rotary" is twisting the ski on the snow. He recognizes the "internal" rotary of parts of the body necessary to edge the skis, etc. PSIA's is considerably different and takes in all rotation of all body parts as well.
I'm not on either side of this dogma thing. I just try to get enough information so that I can compare apples to apples and oranges to oranges.
post #36 of 131
Another thing that comes into play in carving RR tracks is the "local steering angle". (The Skier's Edge by LeMaster)(You have to read it to understand it. It's not "steering" the ski but rather a characteristic of the ski) It's greater at the tip so one can carve a tighter arc with the inside ski by using that part of the ski. How do you use the front? If you were in tennis shoes and you pulled the inside foot back the ankle would flex more and pressure wouldn't change forward. Since ski boots don't have much ankle flexion, pulling the foot back lifts the heel and pressures the toe (where the greater "local steering angle" is)
post #37 of 131
Thread Starter 
Interesting that you would mention that Slatz. The only side of the assumed dogma that I fall on is the 'racer' side of things. I would say I am looking at rotary from the PSIA/USSA point of view... Would the phantom/super phantom be considered on or off the snow? Either way it is a redirection.
Later
GREG
post #38 of 131
Thread Starter 
Quote:
Originally Posted by SLATZ
Since ski boots don't have much ankle flexion, pulling the foot back lifts the heel and pressures the toe (where the greater "local steering angle" is)
Does that still fall into redirection?
post #39 of 131
Quote:
Originally Posted by HeluvaSkier
Would the phantom/super phantom be considered on or off the snow? Either way it is a redirection.
In PMTS the movement is to lift or lighten the tail of the ski while leaving the tip on the snow. This is done in unison with the tipping. There is no rotary movement used.
post #40 of 131
Thread Starter 
Quote:
Originally Posted by Max_501
In PMTS the movement is to lift or lighten the tail of the ski while leaving the tip on the snow. This is done in unison with the tipping. There is no rotary movement used.


So... you're saying that the picture above is not redirection at all? How would you explain this then?

Later

GREG
post #41 of 131
Quote:
Originally Posted by HeluvaSkier

So... you're saying that the picture above is not redirection at all? How would you explain this then?

Later

GREG
I would say that you draw an imaginary lines and want us to ski like this.
I don't think this is what is happening in reality.
There is no contradiction in what Max is saying (except maybe that the lines are not the semi-circles but probably more like a sine curve, and I think that he over-simplified the drawing for the discussion purposes).
So I think that there must be a misrepresentation of the real tracks in the drawing.
post #42 of 131
MAX
According to Harald's definition there is no "rotary". According to PSIA (and Harald) tipping the ski is done by (internally) rotating the femur in it's socket (this is not what Harald calls "rotary" but PSIA does) Tipping the ski rotates it on it's longitudinal axis (PSIA calls this a "rotary" move as well)
I don't agree there has to be "redirection", only tipping and engaging the local steering angle at the tip of the ski. The tracks diverge/converge in this kind of turn because of vertical separation, not because the feet are pointed outward or inward. In fact pointing the toe into the turn is a common mistake people make when learning this. I describe it to my racers as like curling and rolling your little toe back under the foot. I demo it with my hand by touching my little finger to the center of the heel of my hand as I turn my hand upside down. Arcmeister talks about the "kinetic chain", that is, (inside) little toe, ankle, knee and hip(as the hip moves in the outside ski edges leaving the athlete "stacked" over it. (the pressure was on it as soon as the chain started)
In the twenty five or so years I've been at this I've never found a top USSA/USST coach who will engage in this kind of discussion. Rather, as the CDs do, they use drills or describe moves (that may not be what really happens) to get athletes to ski the way they want them to. A few that I have been able to engage don't really have much of a handle on this type of "science" stuff, they're athletic trainers, not technicians.
post #43 of 131
Thread Starter 
Quote:
Originally Posted by Hobbit
I would say that you draw an imaginary lines and want us to ski like this.
I don't think this is what is happening in reality.
There is no contradiction in what Max is saying (except maybe that the lines are not the semi-circles but probably more like a sine curve, and I think that he over-simplified the drawing for the discussion purposes).
So I think that there must be a misrepresentation of the real tracks in the drawing.
Sine curve it is... [best I could do on short notice]
Dark Purple = outside ski
Light Purple = inside ski

See a similarity?


Later

GREG
post #44 of 131
This came up while I was writing. What does the above diagram have to do with redirection? It could show vertical separation if the lines didn't cross I guess. Like I said in my post, "the tracks diverge/converge because of vertical separation, not because the feet are pointed outward and inward".
post #45 of 131
Thread Starter 
Quote:
Originally Posted by SLATZ
This came up while I was writing. What does the above diagram have to do with redirection? It could show vertical separation if the lines didn't cross I guess. Like I said in my post, "the tracks diverge/converge because of vertical separation, not because the feet are pointed outward and inward".
He wanted sine curves, I gave him sine curves... as it turns out it is hard not to make them cross... and doing photoshop editing to 'fix' the transitions would defeat the purpose of the sine curves. I understand what you are saying about the vertical separation and you are right, that is what the divergence is a result of... but the question you should be asking is the track that the inside ski making from the middle of the transition of the turn through the top 1/3 or so of the turn cleanly scribed in the snow or is it 'brushed' as if the ski had been dragged? More on that in the morning.

Later

GREG
post #46 of 131
Cross posted again. Cleanly scribed, not brushed.
Think of it this way. Using the diagram here, as the skis come around and under you the red leg gets shorter but the horizontal element is the same. At transition the red leg is shortened and tipped. As the new turn develops and the angles increase the diagram flips over and the blue leg is the long one. The tracks would then converge to the transition, where they are as wide as the horizontal element, then diverge to the apex where they are as wide as the ski separation.

Darn, link didn't copy. Go back to the post on page one. Sorry.
MOD EDIT : FIXED
post #47 of 131
Quote:
Originally Posted by HeluvaSkier
So... you're saying that the picture above is not redirection at all? How would you explain this then?
Please note that I said no rotary movement was used. The movement is tipping only. The result can have plenty of redirection especially if I happen to be applying alot of counter as used in short rapid turns. But the movement is always the same, just tipping, no active rotary.
post #48 of 131
Quote:
Originally Posted by SLATZ
According to PSIA (and Harald) tipping the ski is done by (internally) rotating the femur in it's socket (this is not what Harald calls "rotary" but PSIA does) Tipping the ski rotates it on it's longitudinal axis (PSIA calls this a "rotary" move as well)
This sounds a bit like knee angulation to me which is not taught in PMTS. Am I misunderstanding what you are suggesting?

When I tip my foot the ankle, knee, and hip stay aligned so my hips drop into the turn.
post #49 of 131
I guess where I'm at Greg, is that whether a few centimeters or meters, there is still guidance going on, and we are really talking about matters of degree at this point. I also see the matter of diverging/converging skis versus constant width as a matter of how much edge angle and the type of turn. Meaning constant width equals more of an upright open parallel type of turn of the spectrum, (instructors bread and butter turn so to speak), but as the turns get more dynamic and the skier moves more inside the turn, the required long leg short leg becomes more nessasary and the outcome will be the converging/diverging of the tracks. The other end of the spectrum.

I still say that in both of these turns and every turn in between there is a constant guiding tension happening in the hips between the legs that is instrumental on the tracking of the skis. We add to it or take away from it to get the desired outcome. That is not to say that a redirecting inside ski pivot can't be utilized coming out of transition but I don't think it is a nessasary component. For that matter, we can redirect both skis if we want, but even then, what maintains the relationship between them after we get them really really close to equal direction and headed the direction we want? Later, RicB.
post #50 of 131
Quote:
Originally Posted by Max_501
This sounds a bit like knee angulation to me which is not taught in PMTS. Am I misunderstanding what you are suggesting?

When I tip my foot the ankle, knee, and hip stay aligned so my hips drop into the turn.
Max, knee angulation may not be taught in PMTS but there is a subtle amount of knee angulation occurring on the left (outside) leg in the pictures of Harald earlier in this thread. I'm not saying it's a lot and I'm not saying there's the slightest thing wrong with it, but that is not a completely straight leg.

There's probably 5-10 degrees of knee angulation going on there. I think that's an example of the minor direction "guidance" or "steering" that most skiers produce through the phases of good turns.

In my opinion, of course.
post #51 of 131
The "kinetic chain" came from a PMTS clinic I took with Arcmeister. It starts at the little toe and progresses. Knee angulation is accomplished by rotating your femur with a bent knee. (rotation again) : One drill that Harald uses is tipping both skis from edge to edge simultaniously standing still on the side of the hill.(try it, it's not that easy) Then he has you do it from a traverse,. No redirection there.
Coaches don't talk about all these hairsplitting things. They just say things like "tip your foot". If you're not doing it right they give you another trick like "curl your little toe back and under.
The thing I like about PMTS is you can't tip your foot without standing on the other foot. In otherwords, you stand on your outside ski to turn Did you ever think about it that way?
post #52 of 131
Quote:
Originally Posted by RicB
I guess where I'm at Greg, is that whether a few centimeters or meters, there is still guidance going on, and we are really talking about matters of degree at this point. I also see the matter of diverging/converging skis versus constant width as a matter of how much edge angle and the type of turn. Meaning constant width equals more of an upright open parallel type of turn of the spectrum, (instructors bread and butter turn so to speak), but as the turns get more dynamic and the skier moves more inside the turn, the required long leg short leg becomes more nessasary and the outcome will be the converging/diverging of the tracks. The other end of the spectrum.
RicB, this is where I live. I am focused on the width of my stance in virtually every turn I make (frankly, I don't think it's possible for me to sense the width of the tracks due to the body dynamics in contrast to the ski/snow interaction). I am not sure how one could focus on constant width, per se, given the more complex body position sensations that one would need to manage.

I find that by maintaining relatively consistent stance width (in terms of "horizontal separation" in this thread), I can keep both skis on the snow, transition using any of the various transition approaches (from the Phantom Move or ILE to a weighted release at the opposite end of the spectrum), and allow the forces to guide my movements. That is not to say that I've "arrived", since I am having to learn to trust my edges more and allow my body to move more inside the turn. But, I'm not going to do that by focusing on track width or even horizontal separation. Or lift/lighten.
post #53 of 131
Quote:
Originally Posted by ssh
That is not to say that I've "arrived", since I am having to learn to trust my edges more and allow my body to move more inside the turn. But, I'm not going to do that by focusing on track width or even horizontal separation. Or lift/lighten.
I find that my body drops farther into the turn when I lighten, tip, and retract the inside leg (while using the appropriate amount of counter acting movements) while gradually extending the outside leg. I don't do anything else to get my hips to drop into the turn, it just happens. I don't worry about my track width but I sometimes will take note of the distance between my legs just to be sure I'm not too narrow or too wide (typically I'm on the narrow side).
post #54 of 131
If one were to TRY to follow these instructions, "tip the inside ski, use no active rotary, do not use knee angulation", one would surely end up dropping their hips into the turn while standing mostly on a long-leg tipped outside ski.

I think the instructions are just a trick to use the kinetic chain to achieve that result, but I don't know; I'm self-taught aside from reading the forums lately.
post #55 of 131
Quote:
Originally Posted by Ghost
If one were to TRY to follow these instructions, "tip the inside ski, use no active rotary, do not use knee angulation", one would surely end up dropping their hips into the turn while standing mostly on a long-leg tipped outside ski.

I think the instructions are just a trick to use the kinetic chain to achieve that result, but I don't know; I'm self-taught aside from reading the forums lately.
Exactly right on, Ghost. If it's done right.

...and not overdone. Or done wrong...
post #56 of 131
Quote:
Originally Posted by Max_501
I find that my body drops farther into the turn when I lighten, tip, and retract the inside leg (while using the appropriate amount of counter acting movements) while gradually extending the outside leg. I don't do anything else to get my hips to drop into the turn, it just happens. I don't worry about my track width but I sometimes will take note of the distance between my legs just to be sure I'm not too narrow or too wide (typically I'm on the narrow side).
I'm using different thoughts, but may get similar results. Deb Armstrong has me moving my hips forward and into the turn by a combination of long leg/short leg and a kind of walking move with the inside leg. She has an article on this coming, I think, so hopefully we'll get some more effective descriptions when that is published.

I don't like to think of lifting or lightening, since that translates to a specific style of transition, and I prefer to play with different transition movements as a way of changing both the path I take and the sensations I develop as a result.
post #57 of 131
Ghost
You're right, it's all about "tricks". It almost never happens as it's described. There are too many fine adjustments that are made automatically. Just like "lifting and tipping are a trick to get you on your outside ski
Another "trick" is tipping without re-directing. Rarely happens but if you think about re-directing you'll get too much. Trying to do it without re-directing and you'll get a minimum amount and a cleaner carve.
post #58 of 131
Quote:
Originally Posted by ssh
... and a kind of walking move with the inside leg.
good idea
my way: put your weight on the inside leg, adapted to conditions, speed etc. either bend your outside knee a bit or pull the whole outside leg backwards. (as you can't move a weighted leg)

post #59 of 131
good for dynamic pressure contribution - utilize the whole sensitive muscles of your feet to get feedback from the pressure of your skis on snow and give a lenghth input to your skis (in this order if your skis allow)

to give an example to understand my poor english a bit better *g* - the pressure contribution on a walking foot.

post #60 of 131
Interesting. Thanks.
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