Learning rotary or not - A Student's Questions - Page 3

Alright, since SSH called me out up above I feel the need to get back to this. SSH is saying that TWISTING (his word) the femurs in the hip sockets produces the same outcome as tipping. This is simply not true because twisting the femur in the hip socket can also result in a pivoted foot (and in my opinion this is the likely outcome if you use those words). In fact, I just asked three different people to twist their femur and all pivoted the foot (not one tipped it). Therefore, the correct statement must be that twisting the femur in the hip socket "might" result in the same outcome on the snow (e.g. tipped skis).

In addition, SSH also states that there is no biomechanical way to tip without rotating the femurs. Is that really a correct statement?

Note, I'm not saying that femur rotation itself is bad.

And I'll add that SSH is a master of misdirection as I'm sure he realizes that femur rotation used for tipping isn't what the OP was asking about.

Couldn't I just lean/tip my whole rigid body over? My skis would be on incresingly higher edge angles the more I tip. Granted I am probably gonna fall over without some counter balancing, but maybe not . I know when I go for a strong, high edge angle water skiing, I don't fall over unless I let go of the rope handle.


JF

The answer is yes,,, at high enough speeds, and/or at low enough edge angles. Generally, though, at the speeds at which recreational skiers carve, and at anything other than low edge rail turns, some rotary assisted angulation is called for. The rotary assisted part is rotation in the femur/hip joint, used to produce a countered state. So in general advice for good skiing, Steve is right. In absolutes, sure, fault can be found. That can be the case in almost every Internet post, though, if finding fault is the goal. Not at all saying you are doing that, 4ster. I know you were just answering the question,,, and you are absolutely right.

Wow,,, that's pretty personal and harsh. I've watched Steve post here for many years now, and I've never seen him be anything but completely honest, sincere and helpful in his posts, and open to listening to and learning from what others say. In this case, I think he was just pointing out that rotary can mean different things. This could be useful for the OP's base of knowledge.

MASTER OF MISDIRECTION. Yikes.

Oh, 4ster, I almost forgot.

The counter produced via femur/hip rotation also helps generate pronation in the outside foot. Very valuable, as it directs pressure right to the business edge of the outside ski. Yet another reason that rotation is so valuable, especially in carving.

Yeah, maybe it was a bit harsh. But I do feel that SSH is ignoring the other and far more frequent use of 'twisting' the femurs that results in a pivot of the foot (rather than tipping).

This is, in fact, a different statement than the one I made. What I said was that the only way to tip the skis is to rotate the femur in the hip socket. 4ster, however, made an excellent point by noting that pure inclination can tip the skis, and he's absolutely right. I wasn't thinking about that kind of movement, for the reasons that Rick pointed out in his post (speed and edge angle). However, my absolutely statement is obviously not precisely accurate, so I'll adjust it to say that typical tipping of the feet requires rotating the femur in the hip socket. See above. You can purely incline to do it. However, I don't think that any of us are suggesting that as the best way to ski all the time. I find the irony of this statement overwhelming.

It is never my intent to misdirect, although a certain group of people holding fast to a faith in a particular Truth about skiing always seem to see my honest efforts at understanding and discerning truth in that way. However, this is an ad hominem attack (attacking the person instead of the idea--a very common tactic on this forum, often although not exclusively used by those same doctrinal folks), and is specifically disallowed by the EpicSki terms.

Absolutely! And thanks for pointing out the weakness in my statement. Is there any other way? Is inclination the typical and effective way to make a carved arc on snow? Weems did tell me a couple of seasons ago that he felt that many skiers do not use inclination enough, and I am one of those people who need to learn to use it more.

You have created a strawman argument again, Max. I did not say that all twisting results in tipping. I said that the only way to tip was to rotate your femur in your hip socket. In that statement, I was corrected by 4ster who pointed out that pure inclination can tip the skis. I will note that you cannot purely incline on packed snow, since your inside leg needs to flex and at that point you'll need to rotate that inside leg's femur in the hip socket to tip that inside ski. However, his point is perfectly valid and shows a weakness in my statement. I do not, however, think it weakens the point.

I am willing to learn if there are other mechanisms for tipping the skis. However, I do not believe that there are. In order to tip your skis at typical recreational speeds and angles, you must rotate your femurs in the hip sockets. There is no other way to do it. Whether it is taught in this way or not is not material to my comments here and to discuss that question is a misdirection or strawman. I am making a simple statement of fact. If you think that you can tip both of your skis on normal packed snow at typical recreational speeds and angles without rotating your femurs in the hip sockets, please explain how you do it. I am all ears/eyes.

I'm quoting this because it is so incredibly valuable and most people have no idea at all how the body works like this. Thanks for the reminder, Rick. I tend to forget how important it is to tie everything in, and this was an amazing insight when I first learned it a couple of years ago.

If you are reading this and aren't familiar with the impact of pronation on edge pressure, read Rick's paragraph a couple of times. It's very useful information that is rarely found. Thanks again, Rick!

I absolutely am ignoring it, since that has nothing to do with the point that I am attempting to communicate.

However, since you insist on bringing it up I will address it as a completely separate point: I absolutely agree that twisting the femur can cause the foot to twist along the plane of the ground (hence, with skis on, to cause the skis to pivot underfoot). Furthermore, I agree that asking people to twist their legs when they are standing will result in that kind of movement. That also has nothing to do with the discussion at hand.

That kind of result is not the only thing that rotating the femur can do (and this is the point I was making; and again, it is a completely separate point).

To every rule there lies an exception



No rotary, counter, angulation. Just pure tipping.

He doesn't have both skis on the snow... and I think that outside femur is rotated a bit...

But I enjoyed skiing with Max...

SSH, when you want to tip your skis do your start by twisting or rotating the femur?

No.

...in fact, Max is a perfect example of someone who gets that, "It's just skiing!" He clearly loves it, has a great time, and doesn't let anything mess with that. Thanks for giving me a smile, Cirque!

It's not so much a strawman argument this time as a simple logical fallacy: "if A then B" does not mean that "if B then A." "If A (tipping) then B (femur rotation--with the noted exception of pure banking)" does not imply that "if B (femur rotation) then A (tipping)." That's pretty basic, and logical errors like this can lead to very wrong conclusions!

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Back to the original topic...!

Following some recent PM's, I thought that the following images might help show the direct, unbroken line of development of basic offensive turns from very first turns (which will probably involve wedges, as I have described above) to high-speed, highly carved, dynamic parallel turns. Fundamentally, they are all the same, but many characteristics evolve due to speed and pitch (and the enhanced forces that result), and skill and sophistication of movement. It's very much like the progression from crawling to walking to running. These are more recent versions of illustrations I first posted many years ago:












I fully expect some controversy!

Please note that these illustrations depict what I call "Reference Standard Turns." They are not meant to suggest that these are the only turns you should try to make, that they are the most fun, or any such thing. They depict the "default movements" of smoothly linked turns meant to control line precisely. They are to skiing what the tuning fork's reference tone is to music. The full symphony of skiing requires virtuouso mastery of all possible "situational movements" and variations on the theme.

Best regards,
Bob

Finally learned something useful from this thread-thanks Bob!

Well said Chuck, the debates are my favorite parts of the Instruction forums, as long as they don't get personal. I hope Bolter comes back. I originally came here for some perspectives on fat skis... I stayed for the debates, & to stay fresh on what things are motivating people in this sport. These "controversies" spark my interest for more knowledge!

Thank you all,
JF

Chuck, thanks for those words.
Debating and discussing ideas is great. A problem arises when it's the people, not the ideas that become the subject of criticism.
If it stays "I disagree with your idea because..." then there is a chance many who want to learn, can.
If it becomes "You are wrong/stupid...", or "you say this" then the only thing that can be learnt is that the poster has a bad attitude to anyone who thinks differently to them.
Tell me what you think, don't try to tell me what I think, or put words in my mouth.

The ones I like the best are where someone explains their point of view clearly, and can point out differences between ideas.


I hope you stick around and enjoy the discussions, learn from them, and get to have fun on the snow!

did we get an answer to this? I am assuming Max is saying the ankles originate the tipping? doesn't that depend on speed, angle, degree of the turn and terrain? My question is what's the difference... is one fundamentally right or wrong- should it always be done one way?

Hi Chuck--

Glad you like the diagrams! If you haven't discovered it, you can click on the images to get a much higher resolution version that you should have no trouble reading.

Regarding the weight transfer--there's a reason your wife has trouble putting 100% of her weight on the outside ski in wedge-level turns. It's not necessary! And it would involve moves that are counter-productive, as I'll try to explain below. Furthermore, if she's just beginning, it would probably challenge her balance uncomfortably, at the very least.

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(Please note that it is also quite possible that she is making defensive, braking wedge turns that are an entirely different animal than what I've described and illustrated. Defensive turns involve pushing the outside ski away, into a skid. Because you're pushing your ski away from you, it is almost impossible to balance on it at the same time, so defensive skiers very often fall to the inside ski. This is a deeper-rooted problem that cannot be solved with just a technical focus--ie. "put more weight on your outside ski.")

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All of these diagrams show passive weight transfers--progressive shifting of the pressure toward the outside ski due to forces of the turn that pull toward the outside (like the weight shift of a car)--not due to any intentional, muscular movement of the skier toward the outside ski.

This distinction is more critical than you may realize. Obviously, experts move their bodies toward the inside of their turns ("inclination") as they balance against the powerful forces of high-speed turns on steep terrain. At very low (wedge turn) speeds, the forces are much, much less. To put 100% of your weight on your outside ski would require a movement in the opposite direction from what experts do--a "negative movement" toward the outside of the turn. It is no more necessary than it would be to tell the passengers in your car "shift left now so we can turn right." Because it is opposite what experts do, it is a dead-end habit that you would have to "unlearn" as you progress.

In terms of the previous discussion, then, the "principle" is smooth, sinuous movement of the body (center of mass) from inside one turn to inside the next. The amount of pressure, and its distribution toward the outside ski, are effects--characteristics that vary with speed, turn radius, and steepness. The diagrams show this. Note that the pressure does not shift 100% to the outside ski in wedge turns. Look at frame 12, where the turn actually begins. There is somewhat more pressure on the downhill ski, largely due to the tilt of the hill as the skier crosses it. The skier moves accurately inside the new turn (left, in this left turn), and the pressure moves progressively toward the right ski, passing through "50:50" at around frame 15. But it may never become 100% on the outside ski until speed picks up somewhat, in which case the skier surely won't be making wedge turns anymore! Consider which direction the skier would need to move in frame 12 to put 100% of his weight on his right ski. Uphill!--the direction opposite from where he's trying to go!

Here's a simple experiment you can do to show how critically important a misunderstanding of cause and effect can be. Part 1: Stand up, in an athletic, "ready" stance, like a football linebacker ready for action. Now, spring quickly to your left. Do it again, and note that every movement you make moves left. Note also that your weight shifts quickly to your right foot as you make your lateral move. Part 2: Stand again in the same ready stance. Now, shift your weight to balance on your right foot. Which way did you move this time? To the right, of course--the opposite direction of your previous movement.

So it is with weight transfers in my "reference standard" (default movement) turns. Weight shifts to the outside ski because of the turn. Weight transfers are an effect, not a cause. If you think you need to shift weight to cause the turn, it will result in completely different and inappropriate (for the purpose of these turns) movements.

On the other hand, none of this should suggest that you should never actively shift weight from foot to foot. Active weight shifts are "situational movements" that you must also master. You may reach "frame 12" in any of my diagrams, for example, and suddenly decide that you don't want to continue in the direction you're going, and you need to change your turn shape quickly. If you wanted to turn more abruptly left than the diagram shows, you'd either flex your downhill (left) leg or extend your right leg, either of which would quickly shift weight to your right foot and push you to your left. Conversely, if you suddenly decided to continue to turn right, you'd shift more weight to your left foot to push you back up the hill.

But by default, the silky smooth, sinuous turns depicted in my "reference standard turn" diagrams involve only passive weight shifts. You "let" the weight move to the outside ski. You don't force it.

Pretty technical, I know, but I hope it makes sense.

Best regards,
Bob

Chuck,

You are not wrong about the purpose of EpicSki. It is a place for open discussion of all ideas about skiing, snowboarding, and related alpine activities (plus the various other topics for which there are forums here).

However, whether or not everyone has noticed it, discussions that turn from being about ideas to being about people personally tend to drive away the very people who could contribute much to the discussions. Besides which, they do not contribute to the conversation, and therefore must detract from it. We have tried for some time here at EpicSki to be open and willing to allow some of this, especially in various areas of detailed technical discussion (that was the primary purpose for creating this separate "Technique & Analysis" forum), but it doesn't work when the various discussions are overrun with either misdirection, illogic, or logical fallacies (I'm sorry for all the terms, but I don't know what other terms to use for what happens!). As a result of these various techniques (whether used purposely or not), discussions are muddied or completely ruined and we end up rehashing them again somewhere else.

I have endeavored to point out where this is happening and how it is happening, and will continue to do so at some level because of the damage it does to discourse. I am also working on other means of communicating this and addressing it when it happens.

Please understand that I am not judging the intents of anyone. I do not know their intent, nor is that part of the decision process. I simply recognize the various methods that are being used to distract or redirect the conversation.

I hope this helps explain my perspective and actions.

I don't know what Max is saying, since he hasn't said anything, yet. He asked what I do, personally, and I don't start tipping from a flat ski by rotating my femurs. However, he may be asking a different question; I'm waiting to see any response to my answer.

I asked the question because I've never heard of someone tipping the skis by twisting the femur.

I tip my skis and I don't twist my femurs either. Sure, the femurs rotate in the hip socket, but I don't twist the femurs to cause the tipping.

There may also be another possibility (not saying that I do this) that isn't solely inclination. What if a skier allows his hips to drop into the new turn while angulating such that the pelvis rotates on the ball of the femur (in this scenario assume the ankle, knee, and hip are all aligned)?

If the femurs rotate in the hip socket, you are twisting your femurs by my definition. Your femurs can't rotate if you don't rotate them, can they? I think that you are thinking "tip" and to "tip" you rotate your femurs.

In my understanding, the pelvis rotating on the ball of the femurs is the femurs rotating in the hip socket. It's the same physiological movement.

I'm gonna jump in here and say no, it really depends on what a given individual skier needs to improve to accomplish their goal. And a different focus may be needed to accomplish the same thing in different skiers sometmes.

I would say that the idea that the "small parts lead the big parts" is generally good advice and a good focus. We don't want to leave behind the small parts as this allows the body to move inside before appropriate edge angle, structural alignment of the body, and pressure has developed. I'm sure you've seen skiers who move their hips laterally before any foot tipping has taken place and then find themselves haveing to push on the outside ski to develope pressure on it and engage the edge. they've moved their hips ahead of their feet. A focus on the small parts leading the big parts may really help the movements to become more progressive and integrated.

On the other hand a focus on moving the hips into the turn early may also be productive and may be needed by some skiers to get to early high edge angles in the turn and full range of motion into the turn. In the end, no matter what your focus, in my oppinion, it should lead a skier to a synergistic "one part moves, all parts move". Where we have a skier moving all parts together appropriately into the turn.

Is anything ever absolute?