How does counteracting tighten up a turn?

[HardDaysNight]

Well... did we settle counteraction? Any comments to my absolutely fantastic discussion above?

I admire your discussion immensely as well as your endurance! The latter I don’t possess personally so I’ll content myself by observing that all high level technical skiers hold the counter action of the old turn through edge change and then actively create the counter for the new turn early in order to position and align their bodies to withstand the forces generated in the impulse phase of the new turn. They do not “ski into counter” and would end up on their arses if they attempted to do so in a properly prepared race course. Of course if one skis with little energy in benign conditions then perhaps the skiing into counter idea gives instructors less to think about and master.

 

[razie]

I don’t see your example here of Lindsey as making your point. She’s in a very anticipated position just before floating. Her pelvis basically stays in position, but her whole body is moving in towards the inside of the coming arc. I don’t see how that would rotate the pelvis even more unless she brings the outside arm way in.

There’s some counter at the image before the gate, then reall st the gate. By the gate her inside thigh is do pushed up that it has to rotate the pelvis out. So, I see it making @geepers ’s point.

If anything, she has negative counter in the first part of the turn there.

Frame 1: hips facing down like the skis.
Frame 5: hips facing down in the same direction, skis turned 90 degrees. This only happens if she actively counteracted or counter-turned the hips or resisted the rotation from the skis, i.e. counteraction or AF rotation. This was a carving turn, the skis were well engaged so cannot be pivoted or redirected "under a stable upper body".
Frame 9: skis turned another 90 degrees, hips facing the same way. This only happens if she actively counter-turned the hips (unwind in this case), i.e. counteraction or AF rotation.
Frame 11: skis turned now some 120 degrees since flat and the hips are still facing the same way. Won't repeat myself, but that only happens if you actively oppose the skis' rotation. Very strongly. At a WC level strong.
Frame 16: you can safely presume it looks much like 5, i.e. skis turned another 90 degrees and the hips nothing. That only happens, if she actively resisted the rotational force coming from an engaged ski, carving at 100 kmh.

I hope this breaks it down enough for everyone to see what's going on...? If it doesn't, let's agree to disagree, then.

It is NOT about the positions (positive or negative counter) but about the movement that counters the action of the skis, i.e. counteraction.

The only other option is that er back was nailed to something that absorbed all the rotational forces coming from the feet turning underneath. At 100kmh, going across the hill 7m at a 25m turn radius.

That would be the ether hypothesis... not based on reality.

p.s. yeah, for the very anal out there, the hips rotate back and forth maybe 20 degrees while the skis rotate more than 270. So not even 10%. I will gloss over that, it goes to human anatomy. This performance is sheer awesomeness, at the limit of human ability... I suck, by comparison! Although... uhh... nah, I suck!

 

[Rod9301]

I don’t see your example here of Lindsey as making your point. She’s in a very anticipated position just before floating. Her pelvis basically stays in position, but her whole body is moving in towards the inside of the coming arc. I don’t see how that would rotate the pelvis even more unless she brings the outside arm way in.

There’s some counter at the image before the gate, then reall st the gate. By the gate her inside thigh is do pushed up that it has to rotate the pelvis out. So, I see it making @geepers ’s point.

If anything, she has negative counter in the first part of the turn there.

You have to maintain the old counter thru the transition, otherwise the skis will slide.

 

[Skitechniek]

There is only one answer to this question backed by research: it increases edge angle, hence tightens turning radius.

https://www.researchgate.net/publication/321368715_Effects_of_Counter-rotation_Position_on_KneeHip_Angulation_Center_of_Mass_Inclination_and_Edging_Angle_in_Simulated_Alpine_Skiing

 

[razie]

There is only one answer to this question backed by research: it increases edge angle, hence tightens turning radius.

https://www.researchgate.net/publication/321368715_Effects_of_Counter-rotation_Position_on_KneeHip_Angulation_Center_of_Mass_Inclination_and_Edging_Angle_in_Simulated_Alpine_Skiing

well... that's for simulated skiers!!! I wonder what it does for real skiers...

 

[razie]

@geepers - your comment to

It is not true that all short turns are rotary based.

was:

Reilly McGlashan has some interesting comments related to this in the new Legacy vids. He talks about short turns by the tracks they leave. One type of track is two thin lines indicative of no (or absolutely minimal) rotary. The comment is that this type of turn is only suitable for intermediate terrain.

Now that's McGlashan commenting. If that's what he feels with his abilities then perhaps we should take note.

@geepers what were you trying to say, with the rotary Reilly comments? What's the time mark? The only comment on that entire 1hr video on rotary, i.e. leg rotation and steering is that it's tricky and he doesn't teach it, instead focuses and teaches only edging - which is what I thought before even watching the video...

Back to Reilly's comments. I don't think he was referring to manual or forceful pivoting or steering. Do you have the clip? - oh, nevermind, it's not public. got it. What exactly is he saying?

here's exactly what he's saying, time mark 37:05

steering movements are very tricky... lot of systems teach this as leg rotation - I personally do not teach leg rotation in my lessons...

... and this is relevant even in the AF vs FA counter discussion, since he specifically says "I don't teach leg rotation"... I guess since it's RMG, we should take note?

 

[geepers]

@geepers what were you trying to say, with the rotary Reilly comments? What's the time mark?

It's in the RM section entitled "Turn Track 4: Carved Short Turns" which starts at 30:42. The track type he is referring to are "two thin edge locked lines in the snow without any tip or tail displacement" so it's going to be closer to pure carving end of the carving spectrum.

The exact quote I am referring to begins at 30:50:

"It is not possible to do this turn on expert terrain nor beginner terrain. Intermediate terrain is the most suitable because a certain amount of speed is required to accomplish it. Beginner terrain you won't get enough speed and expert terrain you won't be able to control the turns properly - too much speed. So it is pretty much a very limited turn only suitable for groomed runs."​

I was unaware that a thread that started with the question:

"I'm very familiar with the notion that what I have come to know as 'counteracting', namely turning my upper body against the direction the skis are travelling, so that I am facing the same direction as the ski bases, has the effect of tightening up a carved turn. What I have never really got my head around is why this should be the case. What is the mechanism at work here?"​

automatically meant that the only thing we were allowed to discuss was AF vs FA. As far as thread drift goes IMHO anything that doesn't discuss how counter increases edge angles is thread drift.

p.s. yeah, for the very anal out there, the hips rotate back and forth maybe 20 degrees while the skis rotate more than 270. So not even 10%

You know I've looked at the image several times. Would you mind drawing some lines on it to show how you think the skis rotated through 270 degrees whilst the hips only managed 20 degrees.

 

[razie]

@geepers - your post reads that Reilly thinks turns with minimal rotary are only good in intermediate terrain - implying that Reilly is endorsing rotary for all other turns and terrain... which he is not - very much the contrary, since he flatly says those skidded turns are not made focusing on leg rotation or steering. Looked like you were quoting Reilly saying that those have minimal rotary and that the others have more rotary...

That puzzled me enough to buy the video to verify. Great video, btw - would have bought it anyways...

Also he doesn't say they only work on the intermediate terrain, only that the intermediate terrain is most suitable, as one has some speed, but not too much. A black run is not necessarily expert nor intermediary terrain, for instance... So, depending on skill, one could make them or not.

About 270? 90 in frames 1-5, 90 in frames 5-9 and 90 frames 9-15,if there was a 15th frame, total 270. By the next fall line, it would have been 360. When someone climbs 3 flighs of stairs and then descends, ending up in the same place, looks like he or she did not do much, although there was a quite some effort...

 

[HardDaysNight]

I don’t have the video but was puzzled by the quote that one cannot make carved short turns on beginner terrain because one doesn’t have enough speed. I suppose he may have a different idea of what constitutes beginner terrain (or what “short” means) than I but I can certainly make carved and pretty damned short turns on the very flattest terrain that exists at PCMR.

 

[geepers]

@geepers - your post reads that Reilly thinks turns with minimal rotary are only good in intermediate terrain - implying that Reilly is endorsing rotary for all other turns and terrain... which he is not - very much the contrary, since he flatly says those skidded turns are not made focusing on leg rotation or steering. Looked like you were quoting Reilly saying that those have minimal rotary and that the others have more rotary...

That puzzled me enough to buy the video to verify. Great video, btw - would have bought it anyways...

Also he doesn't say they only work on the intermediate terrain, only that the intermediate terrain is most suitable, as one has some speed, but not too much. A black run is not necessarily expert nor intermediary terrain, for instance... So, depending on skill, one could make them or not.

About 270? 90 in frames 1-5, 90 in frames 5-9 and 90 frames 9-15,if there was a 15th frame, total 270. By the next fall line, it would have been 360. When someone climbs 3 flighs of stairs and then descends, ending up in the same place, looks like he or she did not do much, although there was a quite some effort...

No, don't put words into my post that aren't there. What I quoted was related to turns that leave two thin tracks in the snow. Nothing more, nothing less.

For what it is worth I think he's right. Steering (or tip and tail displacement) can occur (and certainly does in his skiing) without a direct twisting of the femur. I'm not sure I comprehend his 3 point explanation at this point in time but I experience that type of steerage (without conscious twisting) even at my much lower competency of skiing.

In any event, if we observe the behavior of the ski , does it matter if the steerage (tip and tail displacement) comes from?

Understand your accumulation of angular change. Although I'm not sure it means much. We already know that in short radius turns the upper body will turn out of the fall line much less than the skis whereas in wide radius turns the difference will not be as pronounced.

I don’t have the video but was puzzled by the quote that one cannot make carved short turns on beginner terrain because one doesn’t have enough speed. I suppose he may have a different idea of what constitutes beginner terrain (or what “short” means) than I but I can certainly make carved and pretty damned short turns on the very flattest terrain that exists at PCMR.

Yeah, his comment about not enough speed in beginner terrain makes sense in the context of the vid. Each of the three skiers' segments starts with a discussion about their general thoughts on skiing and what makes a good turn. Rhythm, flow, tempo, amount of displacment, aethestic. That's not his exact words but you may get the point. Later he demos using the flats for carving drills - of course he does a great job but that footage possibly wouldn't attract many subscriptions.

Interestingly I was more intrigued by the upper limit.

 

[razie]

Ok - seems it was some misunderstanding and I'm happy to take the blame.
Your words were the following:

One type of track is [...] minimal rotary. The comment is that this type of turn is only suitable for intermediate terrain.

Now that's McGlashan commenting. If that's what he feels with his abilities then perhaps we should take note.

Still reads to me like you put "rotary" in his mouth. That's a word he does not use at all... but like I said, I'm happy to declare that I misunderstood it.

---

Steering (or tip and tail displacement) can occur (and certainly does in his skiing) without a direct twisting of the femur.

I don't think steering is just "displacing tip and tail" - that's an outcome.

Steering is normally defined by all organizations that I know as a rotary input, by actively turning the legs, to guide the skis around the turn, more than they would carve otherwise. CSIA: "Steering: the blend of edging and pivoting with the control of the resulting pressure. [...] Pivoting: [...] turning the legs in the hip sockets creates a steering angle."
NZSIA: "steering The use of muscular effort to control the rotation of the legs while travelling forward through an arc. [...] In skiing leg steering is an example of torque".

I think it matters a lot how we get the skis to do what they do. Trying to redefine steering to match what Reilly does (no FA rotation), just to say "he's steering" when he specifically says he's not, is not helping the discussion.

The only thing he has to say about steering (and I quote):

steering movements are very tricky... lot of systems teach this as leg rotation - I personally do not teach leg rotation in my lessons...

Like you said, it's Reilly so I'm not very inclined to second guess him right now.

But maybe I'm too anal about it and we could have another thread to clarify this subject, if you'd like, while keeping this one on the AF separation issue at hand...

 

[Noodler]

^^^^^^^^^^^ Thanks for the "rotary" definitions. In my view, for more clarity, I will use the added modifier "active" to rotary, as in "active rotation" of the femurs vs. passive. I hate the term "rotary" because of course there is rotation of body parts in every ski turn. It's just how that rotation comes about where the debate and confusion resides.

 

[geepers]

Ok - seems it was some misunderstanding and I'm happy to take the blame.
Your words were the following:



Still reads to me like you put "rotary" in his mouth. That's a word he does not use at all... but like I said, I'm happy to declare that I misunderstood it.

---



I don't think steering is just "displacing tip and tail" - that's an outcome.

Steering is normally defined by all organizations that I know as a rotary input, by actively turning the legs, to guide the skis around the turn, more than they would carve otherwise. CSIA: "Steering: the blend of edging and pivoting with the control of the resulting pressure. [...] Pivoting: [...] turning the legs in the hip sockets creates a steering angle."
NZSIA: "steering The use of muscular effort to control the rotation of the legs while travelling forward through an arc. [...] In skiing leg steering is an example of torque".

I think it matters a lot how we get the skis to do what they do. Trying to redefine steering to match what Reilly does (no FA rotation), just to say "he's steering" when he specifically says he's not, is not helping the discussion.

The only thing he has to say about steering (and I quote):



Like you said, it's Reilly so I'm not very inclined to second guess him right now.

But maybe I'm too anal about it and we could have another thread to clarify this subject, if you'd like, while keeping this one on the AF separation issue at hand...

"Steering (or tip and tail displacement)" are his exact words and why I wrote that.

The word "steering" occurs a few times - there's even a heading "Swing Movements: Skidding/Steering Variations".

The rest is as you describe. He says it coming from edging and not twisting femurs.

Again I agree with him that this is the case. I also have no issue with the way the CSIA describe it. There's multiple ways to pivot the skis. CSIA Tech Ref #2 "Turning is led by the lower body and the ski design".

Why do you feel it is important how the ski is controlled? If the skis are made to do exactly the same thing why would it matter?

BTW I'm skiing on 67mm underfoot in western Canada atm. Been a bit warmish and the snow is kind of heavy for these parts. Twisting is really hard work in the soft stuff, doing whatever it is we do to get some "steerage" by edging is a lot less effort.

 

[razie]

"Steering (or tip and tail displacement)" are his exact words and why I wrote that.

That's not right, mate. Excuse my precision... time mark 37:45 - he says "the steering angle, or tip and tail displacement, which most people think it's leg rotation, I think happens from... [not giving it up - buy the video!!]". he never says steering is tip and tail displacement... maybe he does elsewhere? What time mark? Lookup steering angle in RLM's bible - it's a physical concept completely different from "steering the ski".

Why do you feel it is important how the ski is controlled? If the skis are made to do exactly the same thing why would it matter?

That's the best trick question I've seen this year (we're just early February in eastern Canada) !!

"Oh, so what do you do, eh?"
"Oh, I teach people how to turn their skis, eh?"
"Oh, cool, so how do you turn the ski, bro?"
"Oh, it doesn't really matter, bro. Just make it do like this, eh?"
"Oh, cool, let me try that".
"Oh? Yeah? Channel12? Ski patrol? Yeah, there's a guy with multiple tibia fractures, dislocated pelvis and what looks like a few torn ligaments hanging out of his knee, on run EasyPeasy, he needs help. Oh, what's that? What was he doing? Oh, I don't know - he said something about turning his skis, eh? God knows what he meant by that, eh? Maybe he was trying to pivot the skis in heavy crud, eh? What's that? Same as the one yesterday? No, yeah, that one paid for lessons, but probably misunderstood steering and did the same thing, poor guy! Yeah? See you later? Ok!



Good one!

 

[François Pugh]

^^^^^^^^^^^ Thanks for the "rotary" definitions. In my view, for more clarity, I will use the added modifier "active" to rotary, as in "active rotation" of the femurs vs. passive. I hate the term "rotary" because of course there is rotation of body parts in every ski turn. It's just how that rotation comes about where the debate and confusion resides.

Since the OP's question has been answered by @Skitechniek , a bit of thread drift is O.K.
Yeah, best to be precise. I like the term "applied rotary", but from years of reading forms, it is clear to me that most people just use the term rotary (and steering) to mean applying a torque through the boot/ski interface from the skier to the ski in the plane of the snow, that causes the ski to rotate about an axis that is perpendicular to that plane, as in if there were no other applied torques or forces, this torque would make the ski spin around faster.

I guess it depends on what you call intermediate terrain.

With regards to non-rotary, non-steered turns, there are limits imho.

One, most multiple lesson takers and accomplished skiers, and even many authoritative ski instructors have come up through a certification system where rotary and steering are so much drilled in that it has become a part of their skiing that is really hard to shake. Many don't even realize they are doing it.

Two, if done properly minimal energy is lost through friction with the snow, meaning you will soon convert all that potential energy due to elevation into kinetic energy due to velocity, and keep increasing speed until you reach a speed limited mostly by air friction. So OK for greens and blues, but crazy fast for typical black slopes except very short ones, and small turns are not possible at high speeds (too much g-force required), so you better have a long radius ski if you want to make good smooth arc-2-arc turns on steep runs ( I love my antique speed skis for that).

If you like bashing into moguls at 60 mph, have at it; I would rather not, better to keep it to speeds where your absorption skills will suffice.

Four, if you have a ski that can handle high speeds, it won't bend so easily at slow speeds, so hard to do on greens with that ski (but easy enough with a softer-flexing ski).

 

[Mike-AT]

I was focusing on counteracting - especially with the hips - during my recent ski vacation week. I'm not sure by how much it can tighten up a turn, but I definitely noticed some higher edge angles, especially in combination with "pulling up" the inside hip side and the resulting strong weight/balance on the outside ski.

Two more observations:

I seemed to get a nice push/rebound into the new turn by a strong counter. Lots of energy unlocked for me. Also, it almost automatically leads to the next turn through relaxing/retraction.

What's not clear to me is to "hold the counter during the transition". How would that work? In the transition you "un-wind", it does not seem to make sense to me to keep the countered position when you want to have a stable and neutral position before you initiate the next turn?

 

[Noodler]

I was focusing on counteracting - especially with the hips - during my recent ski vacation week. I'm not sure by how much it can tighten up a turn, but I definitely noticed some higher edge angles, especially in combination with "pulling up" the inside hip side and the resulting strong weight/balance on the outside ski.

Two more observations:

I seemed to get a nice push/rebound into the new turn by a strong counter. Lots of energy unlocked for me. Also, it almost automatically leads to the next turn through relaxing/retraction.

What's not clear to me is to "hold the counter during the transition". How would that work? In the transition you "un-wind", it does not seem to make sense to me to keep the countered position when you want to have a stable and neutral position before you initiate the next turn?

Hold the old counter until you're on the new edges for that next turn. Then of course you're immediately working on establishing CA/CB for that next turn. The idea is to maintain the counter UNTIL you have established the new turn by fully releasing the old and re-engaging the edges for the new.

 

[razie]

I was focusing on counteracting - especially with the hips - during my recent ski vacation week. I'm not sure by how much it can tighten up a turn, but I definitely noticed some higher edge angles, especially in combination with "pulling up" the inside hip side and the resulting strong weight/balance on the outside ski.

Two more observations:

I seemed to get a nice push/rebound into the new turn by a strong counter. Lots of energy unlocked for me. Also, it almost automatically leads to the next turn through relaxing/retraction.

What's not clear to me is to "hold the counter during the transition". How would that work? In the transition you "un-wind", it does not seem to make sense to me to keep the countered position when you want to have a stable and neutral position before you initiate the next turn?

That sounds about right.

About holding it - it's simple: do NOT unwind.

Watch below, the transition between gates and how she's holding the counter (approximated by keeping the hips pointing to the outside ski, i.e. down the hill at that point)

 

[Mike-AT]

Hold the old counter until you're on the new edges for that next turn. Then of course you're immediately working on establishing CA/CB for that next turn. The idea is to maintain the counter UNTIL you have established the new turn by fully releasing the old and re-engaging the edges for the new.

More focus on counteracting for me:

In my longer turns my separation seems to work fine (decent at least). In a video with shorter turns I realized I initiate the turn correctly (at least in regards to separation), but during the turn I start to rotate and follow the skis, so I lose balance/outside ski pressure towards the end of the turn.

When you speak of maintaining the counter until you have established the new turn - do you mean until the neutral position (release / both skis flat)? Because if I'd hold it beyond that, my upper body would face in the direction of the new turn - which should be avoided?

Do you have a video (link) that shows this concept of maintaining counter into the new turn?

Edit: @razie it is a bit tricky for me to analyze the counter in the picture you posted. To me it looks like counter is maintained in frames 1-3 (starting from the left), and is released (unwinding) in 4+5?

 

[Rod9301]

You should hold the counter until you are on the new edges.
If you don't do this, your skis will slide, if it's icy.