Poster: A snowHead
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How is this guy skiing?
I'm curious to hear what jargon people use to describe various techniques. If you pop over to the epicski forum, they are talking about cross under and cross over<what?>Are they talking a different language or is it just me?
PS I know the link's a few months old, but did the guys from Rossignol break the Speed Record?
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Follow this
link to epic
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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Kit Wong wrote: |
....Are they talking a different language or is it just me?... |
ajvje iaogr crossover rigu crossunder b? ajfeoga ogu sr0b vwf crossover !!!
HTH,
Tom / PM
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Seriously, tho, I would classify the skiing in the animation as crossover. I don't like the terms either, but I understand what they are trying to get across.
IMHO, crossover is when the skier rises a bit during the transition (from one turn to the next). Crossunder is when the skier either does not rise at all, or actually sinks a bit during the transition.
I personally find the next step in the logical process, ie, why rising is associated the name crossover, is a bit confusing. This is because when I and, I suspect, most people think about this, they see the skis and they see the skier, so there doesn't seem to be any logical difference between the skis moving from skier's right to skier's left versus the skier moving from the left side of the skis to the right side of the skis.
My guess is that these terms got introduced when strong up- and down-unweighting became "unnecessary" when skiing groomed slopes of moderate steepness on deeply sidecut skis. Nevertheless, there were still two, less energetic, versions of these moves hanging around, and they needed names.
When going from one carve to the other, if I rise (aka, "extend") a bit to initiate, it feels to me like I'm the one switching sides and the skis are going on their merry way, virtually unperturbed (at least for the moment) by what I'm doing. This is termed "crossover".
OTOH, when going from one carve to the other, if I sink (aka, "flex") a bit to initiate, or, more energetically, actively pull the skis up (aka, "retract") then, it feels to me like I'm the one flying along momentarily unperturbed by the skis switching sides under me, and so this has been termed "crossover".
On deeply sidecut skis, if there is enough space around you, you can be patient and neither rise nor sink - just slowly change edges by a side to side balance change - and that move will also initiate the next turn. That is why the folks on Epic are talking about a spectrum of initiations from full crossover to full crossunder.
Clear as mud, eh?
Tom / PM
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Hmm - to me the animation looks like what I would think of as crossunder. I think of crossover as a deliberate projection of the body across the skis - imagine moving in a steep traverse close to the fall line, a positive movement of your body across the skis (and maybe slightly forward at the same time - a diagonal crossover) will firstly flatten them and then roll them onto the downhill edges - the edge change essential to start the turn towards the fall line.
On the other hand, when skiing down the fall line linking carved turns, I can feel that the skis are moving along their own almost sinusoidal path from side to side beneath me - a definite feeling that they are "crossing under" whilst I just stand in the middle and go along for the ride. The transition from one set of edges to the other must involve some movement of the legs/feet, but since this happens directly beneath the body there is no feeling of a "crossover" movement.
In the animation I see the skis going out to the side but no movement of the skier across. On the other hand my eyesight's not so good these days....
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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I'm with Alan, I reckon that it's a crossunder as the body remains relatively static as the feet appear to pass from side to side underneath. But then again, I'm shortsighted
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Alan and Tigger, if I am on the sidelines looking at the skier (as this animation portrays), and all I look for is the relative amounts of side-to-side motion of the body vs the skis, in BOTH crossunder and crossover turns, the skis will always look like they are moving side-to-side more than the skier. It has to be this way because this (ie, inclination = angulation plus CM lean) is the main way a skier changes edges.
So, the distinction between crossunder and crossover has to be based on something else. That "something else" can be reduced to a difference in pressure control.
In post #45 of the Epic thread mentioned above, Todo says:
"...I think of cross under as releasing pressure to start the turn and cross over as applying pressure to start the turn. ..."
"Releasing pressure" is done by either actively bringing your legs up, or more passively by momentarily "relaxing your legs as if you were going to sink down" just before edge change (aka, transition). Along these lines, in post #42 of the Epic thread, Nolo similarly described the essence of crossunder as a "compression turn".
"Applying pressure" is done by actively extending your legs just before the transition.
In the first case, the sloping distance from the skier's torso to his skis will either momentarily decrease a bit or stay constant through the transition. In the second case, the sloping distance from the center of the torso to the skis has to momentarily increase as he approaches the transition.
It seems pretty clear to me that the skier in this animation is momentarily extending before the transition (ie, edge change) and then settling back down after the transition. This is why I classified these turns as crossover.
Look very closely at this skier and imagine yourself skiing exactly this way. When I do this, I can almost feel myself going (just a bit) up-and-over the skis at the transition, certainly not sinking a bit and momentarily letting pressure off the skis.
As I mentioned in my previous post in this thread, I strongly dislike the terms "crossover" and "crossunder" because they seem to imply that you can distinguish between the two types of turns based only on careful observation of side-to-side movements, whereas, upon closer analysis, it boils down to flexon/extension movements that distinguish the two types of turns.
HTH,
Tom / PM
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Crossover/crossunder are either/or terms that have little evidence in reality to support the either/or, because in reality the two are both/and. Still, crossover was coined to denote the body moving over (across) the skis, and crossunder the skis moving under (across) the body. Unless a skier is demonstrating crossover or crossunder, the two actions tend to be intermingled in a series of turns.
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PM, what does HTH mean?
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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Hope That Helps!
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His technique is quite interesting in CGI terms it's called left leg follows path whilst other leg reacts to body position
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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Wear The Fox Hat, was that for me or was that for nolo, ?
Quote: |
Still, crossover was coined to denote the body moving over (across) the skis, and crossunder the skis moving under (across) the body
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I like(okay, understand) this definition better
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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Kit Wong, that was for nolo.
HTH
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Kit Wong wrote: |
Quote: |
Still, crossover was coined to denote the body moving over (across) the skis, and crossunder the skis moving under (across) the body |
I like(okay, understand) this definition better |
I would argue that this is an incomplete definiton and you need something more to make it complete.
As a specific example, as you begin a RH turn, your skis will always be moving to the left side of your body and your body will always be moving to the right side of your skis whether its a crossover or crossunder turn, so you need something else to distinguish the two possibilities, and that something else is extension / flexion.
This aspect of the transition tells whether the skis are more or less pressured during the transition, and THAT tells you whether they can serve as a good reference point, or whether your CM is a better reference point (in the moving frame of reference of the skier).
Sorry. Being precise is in my blood.
Tom / PM
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You know it makes sense.
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It's okay, Physicsman. I didn't offer it as a definition of the concept, but as an explanation for the terms.
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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"ESA's Technology Transfer Programme"
I wasn't aware that ESA had expanded into the high tech market.
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Poster: A snowHead
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BillA, I must be terribly obtuse tonight. I don't get the "high tech market" comment.
Tom / PM
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Epic Ski Academy ESA
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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BillA,
I still don't get it.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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Of course!!! Sorry for being so thick, BillA.
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Thanks DB, that's it.
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Has anyone noticed the slight A-frame of the "puppet" right at the end of the "entering turn", just before enteringthe first full turn of the movie?
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Physicsman, I think I've got the crossunder (2MB) thing now- I'm a slow learner!
I can now switch fluently from crossunder to crossover with great effect (just as large)
Note:clips same as those used in 'Arm movements thread'
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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Hi Kit - Sorting out up crossunder and crossover between Aug 25, 2004 and Nov 08, 2004 (first and most recent posts in this thread) is indeed a very impressive accomplishment, especially considering that you probably had to search high and low for snow to ski on during this period. Definitely not the sign of a "slow learner" :thumbs-up:
Of course, now that you are starting to bring the microscope of video analysis to bear on your skiing, like technique hypochondriac instructors, you will become painfully aware of the most minor and transient glitches in your skiing, and will be tempted to dwell on them. It is very brave for skiers to post video of themselves.
Of course, posting video of your friends for us to criticize doesn't count since we can have all the fun we want in their absence.
So, why don't we begin there ... With respect to arm motion in your friend, IMHO, I wouldn't focus on that issue in a first-order analysis of his skiing. Rather, on terrain like this, I would probably recommend that he work on:
1) Making larger angles between his upper and lower body. This would achieve larger edge angles between his skis and the snow, and greatly minimize the skidded component of his turns, This will result in more carving and smoother skiing.
2) More patience, more edging, and less steering /skidding in the start of each of his turns.
3) I would like to see him complete his turns pointed further back up the hill to keep his speed in check instead of relying on a heel push / check at the end of each turn (...see the snow flying...).
4) A better (less skidded) turn entry will also result in the need for less heel pushing / checks at the ends of turns.
5) To achieve higher edge angles without banking into the turn, he probably needs to open up his stance a bit, but from the bit of A-framing that I see on just about every turn, he might need to add a smidgen of canting to the inside of each of his boots/skis.
6) Finally, we get to his pole usage, or lack thereof. I don't mind it at all if someone simply decides to abandon pole use when going at a high speed, but your friend seems to vaccilate between ineffective plants and outright pole dragging that never really results in a pole plant. Even worse, when his poles are flopping around behind behind him, his overall balance seems to drift a bit back (as evidenced by the tip of a ski occasionally rising off the snow by an inch or two when viewed frame by frame).
In the case of your second video clip, "great effect", while you obviously have been having success in your work on "crossunder", you apparently have been studying just a bit too hard on "CRISSCROSS", as evidenced by the last frame of that clip.
Nice skiing! It looks like you were having lots of fun that day.
Cheers,
Tom / PM
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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easiski, Hey, I didn't start it! I merely imported it from the States to highlight the seriousness of topics on Epicski. I am guilty of perpetuating it, but only for fun as captured in the last clip, illustrating the new Criss-Cross technique.
Physicsman, Thanks for the criticism....even though I didn't invite any of me! I knew I would get criticised if I didn't put clips of me up while putting on clips of others for criticism. The videos are almost 3 years old; if I recall, the off-piste in St Anton was concrete all weekend so we thought we'd catch some action on the piste. The ski tips lifting is very noticeable in slow-mo, which is due to the sitting back technique; as is the drifting back of the poles. I hope I don't ski like that now-I'll have to use the camcorder this season to find out!
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Physicsman, very perceptive about the canting, as I am an over-pronator. When my physiotherapist did a plaster cast of my feet, she added some serious canting to my orthotics.
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You know it makes sense.
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PM CF your #1 making larger angles between upper and lower body. If I notice an inside-ski-tip lag at turn midpoint so that the 'drawing-in' turn release also has the job of pulling the tips even,
- am I over-rotating the hips on entry?
- should I look for canting correction?
- am I hiding a stem of the inside ski?
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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Kit Wong wrote: |
Physicsman, very perceptive about the canting, as I am an over-pronator. When my physiotherapist did a plaster cast of my feet, she added some serious canting to my orthotics. |
Kit - I hate to ever have to turn down credit, but in this case, unfortunately, it is undeserved. With the single exception of my attempt at humor by referring to the final "criss-cross-over" turn (ie, the fall) in your skiing, ALL of my other comments on technique were about at the skier shown in the video, StAnton2.mpeg, not StAnton3 or StAnton4. I thought the person in the StAnton2 video is a friend of yours, not you.
Sorry if I wasn't clear.
Since you didn't ask for a critique, I didn't offer one, but, as I said, I thought your friend was fair bait for a bit of movement analysis since he/she wasn't around to defend himself and was anonymous.
Tom / PM
Last edited by Otherwise you'll just go on seeing the one name: on Wed 10-11-04 2:03; edited 1 time in total
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Poster: A snowHead
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Easiski - yup, unfortunately, I must confess that I do too carried away with the movement analysis stuff at times, and there are folks even worse than me over on Epic. I guess that what prompted me to go into such detail was that Kit thought that the arm movements were the most outstanding thing about his friend's skiing, whereas I see them being of much less importance in his overall skiing.
Comprex - The skier in the first clip does indeed seem to have excessive tip lead immediately after the transition. I don't think this has anything particularly to do with canting or rotary (stemming). Rather, I think it is because most of his turn initiations are of a diverging tips / skating type, typical of a previous generation racer.
With respect to the participation of his hips in this, I can't tell. They certainly could be a factor, but don't forget that you can slide one ski significantly ahead of the other with minimal angular changes of the hips - you simply adjust the ankle and knee closure angles.
Tom / PM
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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alexpresland, I removed the trailing / from Kit's links as you can see, then they were fine. Seemed to be a glitch in the way media player was trying to load them.
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You need to Login to know who's really who.
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Physicsman, I understand your point, and perhaps I have been looking at too many of Bob Barnes' stick-figure diagrams. I was thinking about legacy technique and equipment, particularly as it might restrict ankle motion.
If you would humour me, and consider the case of the bottom row (excessive forward lean) for a moment?
Consider it in the case of a skier with feet well apart attempting an extension/retraction movement to the side of the Center of Mass. So, what one needs to consider is two stick figures, head and COM aligned, side by side with each other, connected at the hip, with knees bent at different angles.
The knee on the inside of the turn would like to be more sharply bent. A good skier, in staying balanced front-to-back, would wish to compensate for this bend. However, ankle motion to compensate for this knee bend is limited by the forward lean of the boot.
If the skier compensates for the difference using different closure angles for either hip, would this not also imply a tip lead by the -outside- ski?
(We're not allowing a pivot at the toe, or it would be a telemark turn)
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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Alan Craggs,
Quote: |
I removed the trailing /
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, that's perculiar, because I couldn't get the link without the extra '/'
comprex, you're scaring everyone away!
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You'll need to Register first of course.
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comprex wrote: |
...I was thinking about legacy technique and equipment, particularly as it might restrict ankle motion. ...The knee on the inside of the turn would like to be more sharply bent. A good skier, in staying balanced front-to-back, would wish to compensate for this bend. However, ankle motion to compensate for this knee bend is limited by the forward lean of the boot. If the skier compensates for the difference using different closure angles for either hip, would this not also imply a tip lead by the -outside- ski? |
Yup, it sure would, and this is not realized by some instructors. This is exactly why the oft-heard admonishment to "pull back the inside ski" can be difficult for some skiers to do (ie, boots with too little forward flex). Good call.
With respect to the skier in the video, the only reason I gave a noncommittal answer was simply that I couldn't see his hips well enough to tell what was going on.
Tom / PM
PS - I haven't forgotten your email - I've just been a bit swamped at work. Besides, your question almost certainly could benefit from the higher bandwidth of a face-to-face, or even on-the-hill discussion.
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