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Fundamental?

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Uke

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LF,

Yea, one of those nasty four letter words. In this case I would be using the grf to push my body where I want it to go. Directing the trajectory seems much more elegant.

uke
 

Zentune

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LF, I’ve always interpreted Jamt to mean that when accelerating down, the 2 paths will diverge and when accelerating back up, they will begin to converge.

Jamt, is that in the ballpark?

zenny
 

Jamt

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LF, I’ve always interpreted Jamt to mean that when accelerating down, the 2 paths will diverge and when accelerating back up, they will begin to converge.

Jamt, is that in the ballpark?

zenny
Kind of, but its easy to confuse speed with acceleration. When the acceleration up starts is when the vertical force is larger than the body weight (times g and trigonometrics to compensate for slope).
It is best explained by a picture. This is the ensemble average of vertical up acceleration for a group of high level racers in a 10/2 m course. Assuming a body weight of 80kg the up acceleration is pretty much during the turn phase, and the down acceleration in the rest. There is a bit of a plateau before the gate when the force is close to max. This is still before the CoM has reached its lowest position, which is just at the gate.
It is worth noting that the states where the body weight is close to or equal to the corresponding force is passed very quickly, both on the way up and down.
Vertical Force.PNG
 

T-Square

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Skiing is easy: turn left, turn right, repeat.

I’ll add, miss trees, miss lift towers or you’re going to have a bad day.





Had to put the South Park ski instructor statement in there. :D
 

Zentune

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I see why you thought I meant in relation to speed Jamt, my thinking was more like, pressure decreases for a very short time through transition and as the paths diverge and increases as they converge (and as the mass begins to vault back out)...which is sort of aligned with the image you posted.

zenny
 

Doby Man

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Our center of mass IS our momentum and our trajectory is the direction of that momentum. So yes, I would agree with Uke that managing our direction through managing the momentum or trajectory of our CoM is a fundamental dynamic of alpine skiing, advanced as it may be.

Though, I typically reserve the term “fundamentals” for movements unless otherwise indicated such as “fundamental dynamic” mentioned above. My definition of fundamental movements are the movements that must exist for an reasonably competent alpine ski turn to happen. They are (generally): flexion, extension, angulation, inclination, rotary, tipping and skidding. Without anyone of these moves, a competent turn can not be performed. The pole plant is the only fundamental movement that can be skipped for a turn to happen, however, I consider it a true, core fundamental because it is a movement that significantly enhances all the other fundamental movements listed above. It is these fundamental movements that we use to create and manage what I refer to above as “fundamental dynamics” which (generally) include balance, leverage, momentum and separation mobility. These are the dynamics we create that lie between our fundamental movement inputs and the ski to snow interaction output (exchange of forces) we seek. They are the vehicles that turn inputs into outputs.

A good skier is a good “CoM Pilot”. Good piloting of the CoM is the ability to control the CoM’s momentum, its direction and vertical stability regardless of what is happening with the feet and the slope below at any specific point in time. The side view of good mogul skiers provide an excellent example of a stable vertical flight path in the face of abruptly undulating terrain. Though, in bumps, there is very little lateral movement of the CoM and is somewhat one-dimensional in that regard. It seems to be the WC SL and GS competitors that tend to exhibit the greatest skill in piloting the flight path of their CoM in maintaining vertical stability in undulating terrain while also executing a high degree of turn through the facilitation of lateral forces. The steadier the momentum is, the more stable the path of our CoM is and the easier it is to recover from mistakes and unexpected terrain anomalies that disrupt the BoS. It is the momentum of our CoM and how we manage it that is the primary attribute to our state of flow.
 

LiquidFeet

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....A good skier is a good “CoM Pilot”. Good piloting of the CoM is the ability to control the CoM’s momentum, its direction and vertical stability regardless of what is happening with the feet and the slope below at any specific point in time.... WC SL and GS competitors that tend to exhibit the greatest skill in piloting the flight path of their CoM in maintaining vertical stability in undulating terrain while also executing a high degree of turn through the facilitation of lateral forces... It is the momentum of our CoM and how we manage it that is the primary attribute to our state of flow..

What you're saying is absolutely right, except for that "regardless" part.
Good skiers pilot the flight path of their CoM with their feet (and the legs attached to them).
There is no regardless there.

What touches the snow is what controls the flow.
 

Crank

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So most fundamentally - balance. If you want to say dynamic balance sure, but you are moving when you ski so that is kind of implied.
 

Doby Man

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Yes, LF, but don’t we need to maintain flow when there is no connection to the ground? Though, I guess I'm talking more about releasing the connection between the CoM and BoS when a ski slips out from underneath us, something that launches us like a misinterpreted virtual bump or hits something that slows the BoS abruptly so that the CoM can continue as undisrupted as possible. Managing the relationship between the CoM and the BoS is as much about the driving force between the two as it is about separation independence where both can be briefly, “at any specific point in time”, managed independently. While the trajectory of momentum is due to the connection between the two, we can overcome a “BoS hiccup” easier by not reacting/over reacting with our CoM knowing (instinctively) that a final correction can be made within the following turn. Good recovery from mistakes is a primary benefit to flow whether we are Joey the athletic intermediate who can ski fast and keep his Levis from getting wet or the master of flow himself:

 

CalG

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Like aiming the flight of an arrow.

Aim HIGH to hit the target!
 

Jamt

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My definition of fundamental movements are the movements that must exist for an reasonably competent alpine ski turn to happen. They are (generally): flexion, extension, angulation, inclination, rotary, tipping and skidding.
Great post Doby, but do you really count skidding as a fundamental movement?
 

JESinstr

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Doby Man said:
My definition of fundamental movements are the movements that must exist for an reasonably competent alpine ski turn to happen. They are (generally): flexion, extension, angulation, inclination, rotary, tipping and skidding.

Great post Doby, but do you really count skidding as a fundamental movement?

Skidding is a failure to carve.
 

Doby Man

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Great post Doby, but do you really count skidding as a fundamental movement?

Skidding is a failure to carve.

Good question Jamt. Typically tipping and skidding are covered by one fundamental referred to as edging. Edging deserves a spot in the list of core fundamentals because it represents the footwork that needs to be facilitated to control the edges. If you think about it, it is impossible to manage skis without both tipping and skidding. While a skier may be able to ski an easy run with 100% edge locked turns, that would not be true on the majority of terrain and not at all in any race course short of an easy Nastar course. However, I now prefer to define edging in two categories because tipping has somewhat separated itself from skidding with modern shaped skis. I am a tipping centric skier who only skids to create friction for speed control and for no other reason. Whether my edging is controlled by tipping, skidding or a blend, they are movements executed by the feet and ankles. All the other fundamentals are focussed on movements of the body and we need at least one (two for me) that include the feet. Technically, we could include skidding, a rotary motion, in the rotary category and tipping, a lateral motion, in the angulation category but, again, especially today, using our feet to ski is a fundamental that cannot be ignored. Also, these two edging fundamentals bring the ski into our anatomical fundamental movements as they should because the ski is a critical extension of our anatomy and the only one where the rubber meets the road and where the forces we seek are exchanged between the ground and skier.

Now, as a tipping centric skier, my personal list of core fundamentals do not even include the body, They are what we do with the ski as if it is our foot. I refer to them as “clean skis fundamentals”:

1. Tipping - always tipped equal and tipped at a constant rate

2. Left/right pressure control - always outside dominant but always shared for equal bending

3. Fore/aft pressure control - always migrating from tip to tail

4. Relative ski position - always parallel and no or little tip lead

In order to obey these fundamentals, whatever my body does to achieve these results correctly, for the most part, is going to be correct by default. It gives the body freedom to find its own, somewhat skeletally kinetic predetermined path of movement, without cognitive intervention. I believe that many adult advanced intermediate skiers plateau because all the complex anatomical directives become too complicated. I can read it in their words and see it in their movements. As they continue receiving complex anatomical directives from instruction, (many of which never lead to fruition or are sustained in fruition and yet continue to pile up in the back of their minds), that plateau digs itself in for the long haul. We can observe a skier and determine which movements are compensatory and how much DIRT is applied to them to determine how plateaued a skier actually is. The more stubborn the plateau, the more we have to disrupt that person’s frame of reference on technique to make real and lasting corrections. Before that can be done, usually some type of critical change in the thinking of the skier will need to occur. Humans are creatures of habit which does not bode well in the long journey of ski development. If you have been stuck in the advanced intermediate rut, are frustrated with pretzeling your body in every which way and are willing to do whatever you can to get past it, try turning everything upside down and look to the ski. Primates are better tool users than they are performance artists.
 

JESinstr

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Fundamentally, a modern shaped ski is a tool engineered to do only 3 things. Using its friction reducing base, It can slide, both inline with the fall line and perpendicular to the fall line. Using its edges, it can brace perpendicular to the fall line. Or, it can produce a carving state using its base, edges and bending capabilities. It is not designed to skid. Skidding is a transitional gray area between the carving state and the sliding state.

That being said, skidding is something that is part of almost every turn. The question is, do we skid intentionally or unintentionally?

If we have the skill to intentionally skid, we use it as an entry ramp to the carving state or as a controlled exit from same.
Unintentional skidding (whatever the cause) is problematic. Leaving the carving state unintentionally is what happens to many skiers as they pass the fall line and lack the skills to continue carving, thus an attempt is made to achieve a sliding state against the down hill pull of gravity via bracing against the ski. It can also happen due to terrain abnormalities like ice or bumps.

Where @Doby Man may think of tipping as his fundamental to enter the carving state, I tend to look at it from the short leg/ long leg perspective. There is no right or wrong here, just different choices of perspective. A fun discussion to have may be: Does tipping cause shortening or does shortenting cause tipping?

If you think about it, (as long as there is a slope) there will always be a short leg and a long leg unless the skis are pointing straight down the fall line in which case, allows for the sliding design feature of the ski.

As with skidding, The long leg/short leg movements can be intentional or unintentional. Advanced skiers learn to intentionally shorten their inside leg as they enter the carving state. This allows for the production of higher edges by creating an environment conducive to the angulation process.
 
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Uke

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JES,

How about 'Arced side slips'?

uke
 

JESinstr

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UKE, What are arced side slips? if there is forward travel and slipping then by definition it is skidding. But skidding to what end is the question. Never said skidding was a bad thing.
 

john petersen

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skidding is a tactic. ( hopefully) and is useful. it is also necessary for versatility. embrace it. not every turn can or should be perfect. (perfectly round, perfectly arced, perfectly executed )

I dont mind the "regardless" part of Doby's comments. I understand that as we guide or pilot our COM though versatility and experience and of course intent, that a heightened sense of "it does not matter what the feet are doing" is attainable when you are "in the zone". Its a mindset thing. Of course it matters what the feet are doing....but there comes a point sometimes when its the relationship (COM/BOS) that really matters. when things are working in conjunction between the snow, the tool on our feet, our bodies and minds that the separate parts are not the issue, but maintaining the "whole" is what we are after ultimately.

zen, young panda, zen!

;)

JP
 

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