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# Movement During a Turn - Page 2

From the straight run it takes lifting the toe for the first turn. Once the CM starts flowing downhill it leads the way, and hopefully maintains that balanced relationship to the skis. Other movements are made (intentially or not) to interrupt or resist the downhill flow, or reestablish the perpendicular to the horizon. If you return to perpindicular to the horizon, T-Squares "moving back", then you have to make another move to reestablish the perpindicular to the skis relationship. You are more efficient and better balanced if you maintain the "forward" CM over the feet relationship. Here by over the feet I mean relative to the skis, not relative to the horizon.
I would think the CM starts flowing downhill in order to maintain the balance in response to lifting the big toe. The movement across the skis is an artifact that keeps the CM perpendicular to the topsheets and positions the body to best resist the deflecting force of the ski.

This movement across the skis is not the movement that begins the turn -- that was the lifting of the big toe. In other words, this cross-ski movement is part of the balancing act that keeps us over the ski, not the movement that actually drives or initiates the turn.
The question is why do you have to lift your big toe on any ski? Are you skiing with pressure on your toes? If so you are not properly set up in your boots.
It's just one example of an action that may occur prior to turning. Lifting the big toe has a similar effect to tipping the ski onto the little toe's edge.

All this talk about "directional movements accross the skis" made me wonder if some people prefer to use them for turn initiation, or if they were secondary to some other movement that actually initiated the turn.

eg. flexing outside leg, extending inside leg, tipping to new edges, retracting outside leg etc.

I assumed that Kazooski's "lift big toe" was an example of just that sort of move.
Kazooski,

On the Dynamic balance thing anticipation seems a pretty good word to describe planned balancing … but it’s already been commandeered for a particular use in the ski instruction lexicon. I’d be the first to agree that the ‘right amount’ of movement can only be learned thru experience of outcomes (both good and bad).

Also, I like your reference to the “ineffective or counter productive guided discovery” that usually occurs when someone takes a student someplace well beyond their skilled competency. Without appropriate input the student will react through instinct to the balance-challenging terrain rather than through informed understanding and likely develop (and lock-in) bad habits.

I find a level cat-track cutting across a moderate slope works well in teaching F/A balance ideas. I start students with ski tips hanging over the void and boots right at the edge, then talk about what happens the moment they inch forward and take off. I ask them to first launch while standing straight up and feel the force pinning them back as they take off from that position. I have them experiment with adjusting forward a variety of ways (ankles, waist, hips, knees, spine) before inching over the edge. Doesn’t take long before they prefer adjusting forward in advance of the need - using an assortment of joints.

‘Keeping up’ with my skis? Well, in soft snow I find the crawl-stroke works OK, but in very deep snow the side-stroke works way better. In deep wet snow body surfing works best if steep enough.

---
On the issue of whether we actually do move forward and back it might be helpful to look again at Bob Barnes’ stationary Bump Skier animation (the one showing a backpedaling motion of both feet and legs).

That animation shows the feet moving forward and back in the sense of a vertical line drawn thru the skier’s body. Bob could recreate this animation to show a constant position of the feet while the upper-body moves forward and aft. Such a re-creation might also better reflect the internal perception many skiers have of the motion. In the real world our movement pattern includes both aspects occurring at the same time (a whole-skier F/A rotation overall).

This same F/A movement cycle (feet relative to upper-body) occurs in virtually every typical turn although the timing and range varies greatly. Picture a well balanced skier at the Apex of a medium radius turn on a 30-deg slope. Their upper-body will be seen as leading their feet (as seen vertically from the side of the skier) because the overall skier is essentially perpendicular to the slope. Looking at the same skier just as they begin transition (again from the side of the skier) we’ll see the upper-body more directly ‘over’ the feet as evaluated against that same vertical line. This gets back to the idea of our skier rotating forward and backward with the changing F/A attitude of their skis.

---
Another consideration is how turn radius (and therefore movement timing) greatly affect our body’s F/A relationship with our feet.

Larger turns require us to remain more precisely in-sync with the current F/A attitude of our skis. Short turns (especially very short turns) require the skier’s feet to implement a greater range (and rapidity) of F/A motion in relation to the body. Short turns also provide a balancing shortcut as described in the Three-Turns thread…

In a very short turn the lateral motion of the upper-body (at Transition) translates into the body’s F/A position at Apex because the skier's body rotates to face into that direction.

Likewise, permitting the upper-body to continue ‘down the hill’ from Apex-thru-Transition means the skier’s upper-body will have pre-existing lateral momentum (now, across their skis) during Transition. When I’m skiing very short turns my upper-body maintains a largely consistent downhill-progress while I drive my feet fore & aft as well as out, around and back under me during each turn cycle. Timed correctly, the lateral motion of my body at Transition creates my F/A position at Turn Apex - and the forward motion of my body at Apex becomes lateral movement across my skis at Transition.

When things are going really well I never feel like I’m “initiating” a turn because the momentum(s) created earlier flow progressively into the execution of each new turn stage. Kinda like PSIMAN - he doesn’t actually “initiate” a new turn with a conscious movement - each new turn just happens as an integrated outcome of his ongoing momentum.

.ma
Are there other ways to initiate that turn from the initial straight run down the fall line?

Kazooski's lift the big toe/tip the inside ski seems to work. How about long leg/short leg? By this I mean flexing the new inside leg and extending the new outside leg. That is another way to get the COM to move in the direction of the new turn. This is starting a bit higher up on the kinetic chain.
Sure, that will work too. But it has consequences that making turn initiation begin at the feet and ankles do not -- specifically, it introduces uncertainty in your balance.

If you initiate a turn with a movement at the knee, the base of support (BOS) has to either to have been make ready to accept the shift in your balance, or moved to accomodate that shift of balance.

In my mind, the latter choice of moving the feet AFTER your balance has shifted is defensive -- it defends against falling down! In fact, it will be difficult for your body to make other moves until the certainty of balance has been reestablished. When I initiate a turn that way, I feel a definite pause until the edges become engaged -- there is some fun to it, but I feel less than solid doing it.

On the contrary, if I make foot and ankle movements knowing that the directional movements that take me across my skis will be part of the movements I make with the body to maintain balance, then my movements have positive purpose and positive intent: to maintain as opposed to re-establish balance.

Furthermore, I can "aim" the direction these movements will take my upper body by the sort of movement I make with the foot and ankle PRIOR to flexing the knee.

eg. Rolling the foot to the new edges will engage sooner, dorsiflexion will help bring my center of mass (CM) forwards. Varying the amount of rolling/dorsiflexion and flexion will have different results, but a diagonal directional movement across the skis will always occur as directed by the foot and ankle movements. (Assuming that the rate of flexion is not so ridiculous that it overrides the effects of the movements at the feet.)

Note well that the directional movements are subordinate to the movements made at the foot and ankle. I mean if you know that moving the CM inside and forwards is a desireable thing then what would cause me to select any other movement pattern as my preferred/"go to" turn initiation?
Movement patterns necessary to initiate a turn from a straight-down-the-slope run can be modeled on a solid floor. To eliminate the complication of two-footed balance interaction we can best model reality from a single foot.

Try standing on a hard flat floor on just your right foot in an upright stance having just enough flex to model the leg-angles you’d have standing in ski boots. Try to balance over the center of that foot with both arms pressed against your sides, unmoving.

Now, assume you need to move directly to your left from that laterally balanced position quickly and forcibly… and make the move. Be sure not to cheat by "pre-falling" to that side through some subtle cheater-movement - start from a truely balanced position. And dont move your arms when making the move.

Then consider:

- Exactly what biomechanical movement occurred first?
- Did you tip your foot first? If so - to which side?

- Did you “collapse” in some way (a downward/flexing movement) to initiate the leftward move? If so, which way did you collapse your CM (to the left or right)?
- What side of you foot did you move your weight to as you collapsed (indicating which side you tipped your foot to)?

.ma
ma,

yes, there is lots of validity in that, but missing is the inertia of the body travelling downhill. The inertia is so strong, that it can confuse people to think that inertia is the key motive element to turn initiation. It is one important element know doubt, but you still must make the first move.
Big E,

Quote:
 Well, do you lift your big toe first or throw yourself into the turn?
It could be both or none. Directional movement is moving the CM in a direction diagionally and applying force to the sides of the tongue of the boots. Throwing yourself is a gross movement while lifting the big toe is a finer movement. Moving the CM diagionally along with applying some force to the sides of the tongues of the boots (while flexing the new inside leg and extending the outside leg) is more of a controlled harmonious movement.

RW
So Ron, do you view the directional movement of the upper body as an independent act, or is directional movement of the upper body a response to other movements?

Quote:
 Originally Posted by BigE yes, there is lots of validity in that, but missing is the inertia of the body travelling downhill. The inertia is so strong, that it can confuse people to think that inertia is the key motive element to turn initiation.
In the context of a skier making linked turns I think existing Inertia across our skis is the key element driving the entire crossover/new turn initiation. I see the ankle (and up) as tools to manage the process, not the initiator of it in typical linked turns.

Existing momentum (aka: Inertia) across our skis makes deliberate lateral movement entirely unnecessary (again, think PSIMAN). In fact, I'd go so far as to say our perceptions/opinions about which joint we "need" to operate first may actually be an irrelevant argument in the initiation context.

In my view the joints we operate first, second, third (or perhaps simultaneously) define our personal preference in managing the crossover/edge-change process rather than an initiation of that otherwise strictly mechanical process.

More accurately, I 'd say engaging our ankle at a given point in the ongoing crossover process might actively accelerate edge-engagement, even initiate more tangible control over it. The points at which we become actively involved in changing our rate-of-turn stand out and maybe that's why we assign greater emphasis to those points. I think doing so is a matter of intent driving perception rather than a genuine mechanical analysis.

In the straight-run down the slope example above; I don't think forward Inertia makes any difference with regard to the lateral movements needed to initiate a turn.

Wouldn't my flat-floor experiment (described above) conducted on a single ski going straight down the fall-line have the exact same outcomes? If so, we'd surely need to 'make the first move' to cause a turn and I'm pretty sure the direction we first move is not in the direction we seek to turn.

.ma
Quote:
 Originally Posted by michaelA In the context of a skier making linked turns I think existing Inertia across our skis is the key element driving the entire crossover/new turn initiation. I see the ankle (and up) as tools to manage the process, not the initiator of it in typical linked turns.
ma,

If the ankle manages the process, does it also not start it?

I'm not suggesting that inertia is to be ignored. It is a very important element -- managing it is the key to nicely linked turns.

I am saying that movements at the feet should be considered the driving movements that initiate AND manage this cross-over/turn initiation process. The loss of balance and snow contact if they are not are two good reasons why inertia is secondary to the construction of a solid base of support (BOS). The BOS is created and managed first, BEFORE upper body movement, including inertia, is allowed to change the balance equation.

If inertia is placed at the top of the food chain, then our leg and foot movements become recovery moves, no matter how smoothly you can make them. If changes are first made to the BoS that can utilize the inertia of the upper body you will not need to make recovery moves at every turn.

It's called "preparation".
Quote:
 Originally Posted by michaelA Existing momentum (aka: Inertia) across our skis makes deliberate lateral movement entirely unnecessary (again, think PSIMAN). In fact, I'd go so far as to say our perceptions/opinions about which joint we "need" to operate first may actually be an irrelevant argument in the initiation context. In my view the joints we operate first, second, third (or perhaps simultaneously) define our personal preference in managing the crossover/edge-change process rather than an initiation of that otherwise strictly mechanical process. More accurately, I 'd say engaging our ankle at a given point in the ongoing crossover process might actively accelerate edge-engagement, even initiate more tangible control over it. The points at which we become actively involved in changing our rate-of-turn stand out and maybe that's why we assign greater emphasis to those points. I think doing so is a matter of intent driving perception rather than a genuine mechanical analysis. .ma
ma, would you kindly clarify what all this means? In other words, what are you trying to say?
T-Square, RayCantu,
The big toe was just what I grabbed out of the hat. As Big E pointed out, while there are other things one can do to initiate a turn, hopefully we're looking for what is most efficient. To me the closer to the ski that initiation is, the smaller the movement needs to be, and therfore it's more efficient. I try to start with the feet and then fine tune with ankles, knees, and hips.
Can the ankle be the point of initiation? Sure! But I could also initiate by sticking my arm out to the side and still fine tune/compensate with many other body parts and movements.
Isn't the best answer to a question like this "it depends"?
MichaelA I like what you said in your last post.

Now I tried that stand on 1 foot exercise and it doesn't give me a clear answer. I've been mentally chewing on this for quite a while. What starts a movement? If you do the isometric exercise of pushing your hands together and you relax your right arm ,what happens? Both hands move to the right. If you start again but instead of relaxing your right arm you push harder with the left, what happens? Your hands move right. Does movement start because I exerted a force with muscles or because I stopped resisting a force?
Standing on 1 foot, do I start moving because I tightened muscles of the shin or relaxed calf muscles?

It seems that relaxation is more efficient then applying more force. Resisting movement takes more energy then letting gravity do the work.

While skiing, efficiency and good balance come from relaxing instead of resisting.

Back to instinct. Instinct causes us to do things to resist falling. The instinctive move when we slip walking on ice is to throw hands out to the side, tuck your chin down and lean back. Hmm! There's that darn movement to the back again.

In my straight run, if I relax muscles in my right legg I'll start to turn right. I guess I disagree with your last statement MichaelA.
BigE,

Quote:
 So Ron, do you view the directional movement of the upper body as an independent act, or is directional movement of the upper body a response to other movements?
My answer lies in post #40. It also sounds like you have the answer in mind, so why ask?

RW
You're right, I would have done better asking for clarification.

To me, post 40 looks like these are two distinct movements organized to move in concert: the movement at the feet and the movement across the skis.

My answer is that an effective diagonal movement is initiated by the movements at the feet, which prepares the base of support (BOS) for the movement across the skis, and helps guide the direction of the upper body.

Sure anyone can ignore preparing for the movement into the turn by not moving the feet/ankles first, but at the cost of balance. IMO, treating the two movements as independent allows for those undesireable consequences.

My answer is that they should not be considered as independent movements. Sequenced movements at minimum, but I consider them more cause + effect -- the movements at the foot cause effective directional movements across the skis.
Quote:
 Originally Posted by BigE If the ankle manages the process, does it also not start it?
In my view, nope. I see them as separate ideas entirely. I’m not trying to critique the use of any particular joint or appendage as being the preferred guidance mechanism - just introduce the idea that directional guidance itself is simply management of ongoing momentum. (BTW: I realize you fellows all get the whole inertia thing - I’m just exploring the idea to clarify things, not ‘explaining it’ to anyone in particular. )

If a large beach-ball is rolling down a mild slope and I reach down to guide where it’s going I’m ‘managing’ its direction - even though I didn’t ‘start’ it rolling nor did I direct where it was initially going. I just intervened and applied my own preferential guidance at some point. I could ‘guide’ it with my finger, my hand, or my elbow - doesn’t really matter; the act of guiding is being introduced at a given point. That is how I perceive my own skiing: Guiding (sometimes forcibly) my ongoing momentum into whatever direction I choose to go. It just happens to be a much more continuous management process than the beach ball example.

---
Remember all those past debates related to “where a turn begins”? Some people describe the start of a turn as being from Transition, onward. Others describe the start as being the moment a skier ‘gives up’ on the old turn. Some define the meaningful start of a new turn as being at old-turn Apex. Still others focus on the edge-change event regardless whether this occurs actively or passively. We move our thinking preference around so easily because it’s an ongoing, integrated process to begin with.

Take the sequence . . . T k P z T k P z T k P z . . .

This is an ongoing sequence so we can pick any arbitrary letter as our starting point. Our selected point of ‘start’ is simply preferential. So long as we describe the sequence accurately our cyclical description remains correct. We can take the letter ‘z’ and discuss its merits, its contribution to the cycle, its flaws and its relationship to neighboring letters. ‘z’ may be wholly practical and useful as a starting point since we need to start somewhere in describing our sequence, right?

Inertia/momentum is another ongoing thing. There is no start nor stop to it from one turn to the next. All we do is intervene (periodically or continuously) to guide our momentum in one direction or another. Managing ski tilt, rotation and pressure uses the snow to redirect our momentum. I absolutely agree with the statement that managing momentum is the key to nicely linked turns. I’m simply directing attention to the separate nature of ongoing momentum vs. the control/guidance mechanisms that manage the ongoing momentum.

BigE mentions ‘loss of snow contact’ and I think that’s a good way to disassociate the two.

Crossover momentum will continue despite momentary loss of snow contact (picture a jump-entry turn) and directional control returns only when we touch down. We may therefore perceive the ‘start’ of our new turn to be the moment we’re able to start our guidance of the new turn. If we continuously manage our directional momentum right through Transition it gets fuzzier. There would be no ‘start’ of guidance because there was no ‘end’ to earlier guidance. This gets us back to the debates mentioned above: where does the process really begin? I say it begins the moment we push off from standstill, leaving us only with continuous (cyclical) guidance thereafter.

Quote:
 Originally Posted by BigE If inertia is placed at the top of the food chain, then our leg and foot movements become recovery moves, no matter how smoothly you can make them.
Exactly!

I think they are! By labeling them “Recovery Moves” you paint them a nasty color but the fact is we’re always “recovering” our balance while skiing - we’re doing so continuously. It’s just a matter of degree between ‘Guidance’ and ‘Recovery’ (though perhaps quite a big one at times ).

Replace the word Recovery in your quote above with the word Guidance and re-read it. It will then say exactly what I’m saying.

So when does a movement cross the line from Guidance to Recovery?

I normally associate a 'big imbalance' being corrected to a lesser state of 'imbalance' as a Recovery Move but since we’re never actually in perfect balance anyway I know this is merely a judgmental decision about what “big” means on my part.

Better skiers are more consistent and maintain a tighter tolerance with respect to balance deviations while less skilled skiers endure less consistency and a looser tolerance. When guidance corrections to momentum are small it takes a practiced eye to see and analyze the smaller magnitude of ongoing errors. When guidance corrections to momentum get big enough, everyone can see and recognize them easily.

BigE, I’m not suggesting your perspective is ‘wrong’ in any way. I often teach from that very same perspective after deliberately selecting some ‘z’ as my starting point in a movement pattern or technique to explore. I’m just trying to describe the larger (continuous) picture within which we necessarily select smaller sub-segments to describe, discuss and define techniques as we teach them. I think you (and everyone else) will agree that the effectiveness of ankle articulation at new-turn entry is highly dependant on the magnitude and direction or our overall momentum going into & coming out of Transition. We are merely snatching a preferential selected segment of the ongoing process to elaborate our ideas with during discussion.

During any given run, I perceive my linked turns as continuous cyclical transformations in Fore/Aft & Lateral momentums as well as continuous cyclical rotations about all three axes… but then, my own brain may well be bwoken...

.ma
Quote:
 Originally Posted by michaelA I’m just trying to describe the larger (continuous) picture within which we necessarily select smaller sub-segments to describe, discuss and define techniques as we teach them. I think you (and everyone else) will agree that the effectiveness of ankle articulation at new-turn entry is highly dependant on the magnitude and direction or our overall momentum going into & coming out of Transition. We are merely snatching a preferential selected segment of the ongoing process to elaborate our ideas with during discussion.

Please, ma, not everyone agrees. I certainly don't.

Might we step back a bit? Your post #42 still isn't clear to me.
Kazooski,

Picture a free-standing floor lamp with a 6-inch square base. The lamp doesn’t tip sideways because its CM is supported equally on both sides of the square base. Assuming the base has a controlled servo hinge just above it, which way would that base have to articulate to cause the lamp to topple over to the north? As I see it, the base needs to push down on the opposite side (south) to fall over to the north.

In this case the lamp is being toppled over strictly due to Base-of-Support changes - no pre-existing momentum (of its CM) to either side to make use of. The motive ‘toppling’ force is entirely internal. This is equivalent to a skier on one ski going perfectly straight in perfect lateral balance then desiring to initiate a turn. Somehow, that skier must (at least briefly) collapse support under the side of the ski corresponding to the desired turn direction - or must press the opposite side of the ski downward.

The concept is mechanically accurate but presents a problem to figure out... If a perfectly balanced skier wants to ‘go left’ from that perfectly balanced position they must first tip the ski onto its right edge in order to initiate the toppling-over process to the left just as the lamp must do.

This opposite-move needn’t be large nor long in duration but it must be large-enough\long-enough for the skier’s CM to move beyond the left-side of the ski. Having tipped the ski briefly to the right the ski will begin carving slightly to the right - thus moving the ski itself to the right while our simultaneously toppling CM is moving to the left. Once our CM is past that edge (or has enough momentum to make it past) the toppling process will continue to the left even if we now tip our ski entirely onto its left edge and continue with our left turn. Bear in mind that we're only talking about a lateral move of an inch or so to accomplish the necessary imbalance.

Getting back to the flat-floor standing-on-one-foot example, try to sense where the pressure is under that foot when you’re well balanced as compared to the moment you initiate a movement to the side. I think you’ll sense a brief increase in pressure under side opposite to your desired direction of movement.

The same thing happens on a single ski when going straight because there is no existing sideways momentum to work with. In fact, quite often in a linked turn the skier has too much lateral momentum across their skis and they end up having to twist the skis into the fall line right away to maintain balance.

Does that clear things up?

.ma
Quote:
 Originally Posted by michaelA If a perfectly balanced skier wants to ‘go left’ from that perfectly balanced position they must first tip the ski onto its right edge in order to initiate the toppling-over process to the left just as the lamp must do. Does that clear things up? .ma

I've skied and taught for a long, long time, and nope, NEVER experienced having to do the above or even seen the above.

Anyone else? Bueller?
Quote:
 Originally Posted by whygimf Please, ma, not everyone agrees. I certainly don't. Might we step back a bit? Your post #42 still isn't clear to me.
Sure, that's fair.

I guess I was taking it for granted that everyone would go along with the idea that ...

"... the effectiveness of ankle articulation at new-turn entry is highly dependant on the magnitude and direction of our overall momentum going into & coming out of Transition."

In my own view, the quality of new-turn entry is directly dependant on the outcome of our transition from the old turn. If we muck up our momentum during transition, I believe it will have a direct impact on how well our new turn entry comes about. I also see the quality of our turn entry as having a direct impact on the middle of our turn, and the middle having a direct impact on the finish of the turn. In each phase I see the skier's current momentum in that phase as the key element in determining "where they can go from there" with least effort (eg, defining their options).

How do you see it? Do you see entry into a new turn as being unrelated to the quality of transition? Do you see the skier's momentum during transition as being unrelated to the quality of new turn entry?

---
I just posted a little more on ideas related to post 42 so let me know if it comes together from that or not. If not, feel free to point out any inconsistencies with reality that you see. Not always easy to keep it brief *and* fully accurate.

The gist of what I've presented above is that I see our movement patterns as being guidance mechanisms that manage existing momentum rather than actually 'creating' turns, 'stopping' turns, or 'starting' turns (once the skier is already moving).

Sorta like a marble rolling around a figure-eight pattern in a bowl. We might guide the marble's existing momentum along a new path rather than actually 'making' it follow a new path.

I realize this may seem more philosophical than material but I think it changes the skier's focus from 'making motion happen' to 'guiding & re-directing existing motion' - a very different perspective.

.ma
whygimf,

... never experienced it - or never noticed it? Did you try the flat-floor experiment on one foot?

Even if on two feet - doesn't the foot opposite your desired direction of movement receive more pressure on it the moment you make the move to the side? Even briefly?

.ma
Quote:
 Originally Posted by michaelA In my view, nope. I see them as separate ideas entirely. I’m not trying to critique the use of any particular joint or appendage as being the preferred guidance mechanism - just introduce the idea that directional guidance itself is simply management of ongoing momentum. (BTW: I realize you fellows all get the whole inertia thing - I’m just exploring the idea to clarify things, not ‘explaining it’ to anyone in particular. )
This makes for a huge difference in approach, and I think in results.

Quote:
 Originally Posted by michaelA If a large beach-ball is rolling down a mild slope and I reach down guide where it’s going I’m ‘managing’ its direction - even though I didn’t ‘start’ it rolling nor did I direct where it was initially going. I just intervened and applied my own preferential guidance at some point. I could ‘guide’ it with my finger, my hand, or my elbow - doesn’t really matter; the act of guiding is being introduced at a given point. That is how I perceive my own skiing: Guiding (sometimes forcibly) my ongoing momentum into whatever direction I choose to go. It just happens to be a much more continuous management process than the beach ball example.
Sort of a red-herring I think. The ball cannot alter it's base of support (BOS) -- we can.

Quote:
 Originally Posted by michaelA --- Remember all those past debates related to “where a turn begins”? Some people describe the start of a turn as being from Transition, onward. Others describe the start as being the moment a skier ‘gives up’ on the old turn. Some define the meaningful start of a new turn as being at old-turn Apex. Still others focus on the edge-change event regardless whether this occurs actively or passively. We move our thinking preference around so easily because it’s an ongoing, integrated process to begin with.
I thought that this was resolved a long time ago -- the turn starts where the old one ends. The old one ends when the center of mass (CM) is released from it's arc.

Quote:
 Originally Posted by michaelA Take the sequence . . . T k P z T k P z T k P z . . . This is an ongoing sequence so we can pick any arbitrary letter as our starting point. Our selected point of ‘start’ is simply preferential. So long as we describe the sequence accurately our cyclical description remains correct. We can take the letter ‘z’ and discuss its merits, its contribution to the cycle, its flaws and its relationship to neighboring letters. ‘z’ may be wholly practical and useful as a starting point since we need to start somewhere in describing our sequence, right?
Again, this is a red herring, as the movement pattern of the feet after inertia causes the CM to cross the BOS is different from the movement pattern of the feet that reacts to the CM to crossing the BOS.

Quote:
 Originally Posted by michaelA Inertia/momentum is another ongoing thing. There is no start nor stop to it from one turn to the next. All we do is intervene (periodically or continuously) to guide our momentum in one direction or another. Managing ski tilt, rotation and pressure uses the snow to redirect our momentum. I absolutely agree with the statement that managing momentum is the key to nicely linked turns. I’m simply directing attention to the separate nature of ongoing momentum vs. the control/guidance mechanisms that manage the ongoing momentum.
I prefer to create a sequence of causes and effects, as opposed to react to the effect. IOW, move the feet to cause the CM to begin crossing over, not catch the CM after the fact.

Quote:
 Originally Posted by michaelA BigE mentions ‘loss of snow contact’ and I think that’s a good way to disassociate the two. Crossover momentum will continue despite momentary loss of snow contact (picture a jump-entry turn) and directional control returns only when we touch down. We may therefore perceive the ‘start’ of our new turn to be the moment we’re able to start our guidance of the new turn. If we continuously manage our directional momentum right through Transition it gets fuzzier. There would be no ‘start’ of guidance because there was no ‘end’ to earlier guidance. This gets us back to the debates mentioned above: where does the process really begin? I say it begins the moment we push off from standstill, leaving us only with continuous (cyclical) guidance thereafter.
Transition only gets fuzzy if you try to bring ideas together that ought to remain separate.

Quote:
 Originally Posted by BigE If inertia is placed at the top of the food chain, then our leg and foot movements become recovery moves, no matter how smoothly you can make them.
Quote:
 Originally Posted by michaelA Exactly!I think they are! By labeling them “Recovery Moves” you paint them a nasty color but the fact is we’re always “recovering” our balance while skiing - we’re doing so continuously. It’s just a matter of degree between ‘Guidance’ and ‘Recovery’ (though perhaps quite a big one at times ). Replace the word Recovery in your quote above with the word Guidance and re-read it. It will then say exactly what I’m saying.
Then I wholeheartedly disagree with that position. Recovery is not guidance. Guidance is what the initiating movements at the feet/ankles provide. Recovery is a reaction to the inertial path.

Quote:
 Originally Posted by michaelA So when does a movement cross the line from Guidance to Recovery? I normally associate a 'big imbalance' being corrected to a lesser state of 'imbalance' as a Recovery Move but since we’re never actually in perfect balance anyway I know this is merely a judgmental decision about what “big” means on my part. Better skiers are more consistent and maintain a tighter tolerance with respect to balance deviations while less skilled skiers endure less consistency and a looser tolerance. When guidance corrections to momentum are small it takes a practiced eye to see and analyze the smaller magnitude of ongoing errors. When guidance corrections to momentum get big enough, everyone can see and recognize them easily.
Skiing in a perfect state of balance is the goal. Better skiers do it all the time - they are in control of their balance, not continually reacting to "errors". This is the root of the disagreement: Making corrections to your inertial path (which IMO you've mislabelled as guiding) vs causal control of the intertial path by altering the BOS.

Quote:
 Originally Posted by michaelA BigE, I’m not suggesting your perspective is ‘wrong’ in any way. I often teach from that very same perspective after deliberately selecting some ‘z’ as my starting point in a movement pattern or technique to explore. I’m just trying to describe the larger (continuous) picture within which we necessarily select smaller sub-segments to describe, discuss and define techniques as we teach them. I think you (and everyone else) will agree that the effectiveness of ankle articulation at new-turn entry is highly dependant on the magnitude and direction or our overall momentum going into & coming out of Transition. We are merely snatching a preferential selected segment of the ongoing process to elaborate our ideas with during discussion. During any given run, I perceive my linked turns as continuous cyclical transformations in Fore/Aft & Lateral momentums as well as continuous cyclical rotations about all three axes… but then, my own brain may well be bwoken... .ma
I do not think that selecting arbiratrary points in the sequence of events is effective. Nor do I think that teaching in general terms from which no clear direction can be discerned is useful -- eg. "continuous cyclical transformations of momentums" -- poetic yes, but IMO, not useful.

I prefer to teach by selecting points in which major events occur, demonstrating movements that occur between those points and then focussing on the connective actions. That means to focus on preparatory moves in anticaption of the next movement in the sequence.

This is precisely why I will not teach reactive moves:

We need to clarify the causal connection between our actions and the reactions of the skis and body, as opposed to make movements in response to the actions of the skis and body. In particular, how changes made to the BOS affect the path of the CM.
MichaelA,
You are correct that if I want to move left I will experience more pressure on my right foot. However that increase in pressure is the result of reducing pressure on the left foot. My experience skiing is that starting with equal pressure on both feet and pressure evenly distributed on each foot, if I tip (supinate)one foot to the outside, a turn begins before pressure builds on the other foot. No where have I moved anything right in order to move left. In fact the first move of tipping the foot is in the direction of the turn.

BBarnes provides a pretty clear explanation of this in his encyclopedia also. Bob's might be better because it includes a pretty girl.
This thread has turned surprisingly complicated. How does the CM get from the inside of the turn to the outside? Simple, the turn must be released before this will happen naturally. In my case I use a flexing (relaxing) of the legs to release the turn. When I do this the CM is released and starts to move across the skis. I don't have to tip at all to make it happen.
Max,
You're right Max. We're really drifting away from T-Square's question.

I think what we may be chewing on here is, if you can stay properly balanced over your skis the actions we spend so much time debating, CM cross over, edge release, pressure control, what's the key 1st move to initiate a turn, etc. go away. Or maybe take care of themselves. The key is being "properly balanced". I believed I have experienced that state but rarely can repeat the experience, especially when the hill is steeper. To get there involves skiing with no defensive movements/ no fear, total confidence. I was able to do this once in front of a D-teamer who later said I was modeling skiing just the way they would like us to. When skiing this way it feels so incredably easy.
Why can't I do it all the time? I'm human. There are a lot of instinctive, self preservation movements we all do, and I'm not so good at skiing that I can overcome these instincts all the time.

Imagine pushing a car. You're leaning forward. Your whole body is in front of your feet. You don't feel to uncomfortable doing this right? Now imagine pushing that car down your favourite ski run. Doesn't feel so comfortable now with your body in front of your feet does it? Yet the angle of your ankles is the same as when you push the car on flat ground.

That sensation of leaning forward with ankles flexed like they would be while pushing the car is how I feel when I'm doing it right. And my body stays in front of my feet the same as it would if I was pushing the car.

Back to T-Squares question? You don't have to move forward, relative to your feet, if you stay forward in the first place.
Quote:
 Originally Posted by KAZOOSKI Max, Would you say that the tipping of your skis is an outcome from your flexing leggs that allowed your CM to cross over your skis?
If I did absolutely nothing during the float then yes. However, I actively and aggressively tip my new inside foot to the LTE so that my foot tipping leads the hips.
Quote:
 Originally Posted by michaelA When things are going really well I never feel like I’m “initiating” a turn because the momentum(s) created earlier flow progressively into the execution of each new turn stage. Kinda like PSIMAN - he doesn’t actually “initiate” a new turn with a conscious movement - each new turn just happens as an integrated outcome of his ongoing momentum.
I think its unlikely that your turn transitions resemble PSIMAN. Consider that he is basically a weeble on skis. His CM is very low (much much lower than ours) and he is supported by a wide base, so when he tips to the inside the forces have a bias to pulling him back upright even when his speed is decreasing. OTOH, as a human skier using a naturally upright stance (which has a high CM) we find that leaning to the inside causes us to fall to the inside when the turn forces are decreasing. As humans we must do something to release the previous turn or we will carve back up hill and fall into the turn.

So, how does Weeble-SkiMan release a turn? I don't think he does. I think the physics would support the notion that he rides the turn until he reaches a point that gravity pull him back to flat and then he topples into the new turn (this is not a result of releasing momentum but a result of being tipped and released with gravity pulling him into the turn - "weebles wobble"). As a human its impossible to ski like this when in a natural upright position because of the higher CM. Perhaps if I adopted a super wide stance and squatted down as low as I could get while Keeping the legs and upper body totally cocontracted (to create a super rigid platform) I could pull off this type of turn ending/beginning. But I have my doubts.
BigE,

Quote:
 To me, post 40 looks like these are two distinct movements organized to move in concert: the movement at the feet and the movement across the skis.
Actually, post 40 refers to flexion and extension of legs and ankles as the base of directional movements.
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 Moving the CM diagionally along with applying some force to the sides of the tongues of the boots (while flexing the new inside leg and extending the outside leg) is more of a controlled harmonious movement.
I should clarify by stating Moving the CM diagionally and applying some force to the sides of the tongues of the boots (flexing the new inside leg and ankle and extending the outside leg and ankle) is a more controlled harmonious movement.

The feet ( by use of the ski edge) are involved my supplying the base of support for such movements .

RW
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