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The final word on Steering

post #1 of 21
Thread Starter 

I often see and hear instructors and expert skiers explain that a steered turn involves leg rotation through out the turn. That one element of steering is pivoting/rotation. My question is now, how can you keep rotating your legs through out the turn if its a very long and wide and slow turn? In a short turn its different because there you turn your skis from side to side by rotating your femurs in the hip sockets under a stable facing down the hill upper body but in a wide turn where the upper body stays square to the skis through out the whole turn.... What do you guys think?

post #2 of 21

Well I think that yours was not the final word. :) Here's my quick 2 cents...

 

There's a yooge difference between letting the skis turn the legs underneath the hips, slightly resisting that turning force in the hips (or feet), slightly adding to that turning force (aka waist steering or in the feet)  and turning the legs/feet to force the skis to skid. All of these variations involve legs turning underneath the hips and all methods can be used to steer a turn (although I would have to argue that in order to steer when there is no intentional control of leg rotation beyond what the ski is causing, one must use control of edge angle or ski bend to affect direction change beyond that dictated by the shape of the sidecut).

 

Regardless of the technique used, the length of the turn is irrelevant. In general, the longer the turn is the more subtle the movement needs to be in order to not run out or range of movement before the turn is over. In general we strive to make virtually continuous movements of body parts with joints only stopping movement to change direction (e.g. of rotation).

post #3 of 21
The rotational effort of steering does not have to involve displacing the toes more and more from their alignment with the body.. It can just become a steady steering pressure.
post #4 of 21
Steering involves rotational forces that can vary. Edge grip changes how that force effects what the skis will do. So does swing weight. Even going straight involves rotary forces to keep the skis "on line". (Think about the skis wobbling as they run across small bumps and such).
So even though you may not actively twist them, just holding them in place is steering them. Especially during a turn. Oversteer, or understeer and you disrupt the intended turn. So to say we don't steer the skis at all time is like saying we don't steer our cars as we drive.
post #5 of 21
Thread Starter 
Quote:
Originally Posted by justanotherskipro View Post

Steering involves rotational forces that can vary. Edge grip changes how that force effects what the skis will do. So does swing weight. Even going straight involves rotary forces to keep the skis "on line". (Think about the skis wobbling as they run across small bumps and such).
So even though you may not actively twist them, just holding them in place is steering them. Especially during a turn. Oversteer, or understeer and you disrupt the intended turn. So to say we don't steer the skis at all time is like saying we don't steer our cars as we drive.

 

When you steer your car into a turn you initially turn the steering wheel a certain amount but after that you stop turning it and hold onto its position. If you just kept on turning the steering wheel the car would be turning tighter and tighter. Same thing in skiing....

post #6 of 21

Except that would be called "park and ride".

post #7 of 21
Quote:
 in a wide turn where the upper body stays square to the skis through out the whole turn

What is the biomechanical reason to keep the upper body square to the skis through out the turn?

 

In any case, what you're suggesting is against the law.  Newton's third law.  "For every action, there is an equal and opposite reaction."  You can only turn the feet if the upper body is anchored (which it can't be while skiing) or turning the other way in proportion to the relative mass of each part--feet & skis vs. upper body.

post #8 of 21

SoftSnowGuy:  You can read the entire thread here:

 

http://www.epicski.com/t/147200/help-with-counter

 

But what I came away with from that thread (with a little embellishment of my own from what I teach students) is that humans are forward-facing predators.  Meaning that our eyes are in front, and our hips, knees and toes face forward because we are made to chase and catch things rather than eyes-on-the-sides-of-our-head designed to run away from things that are trying to catch us (like horses, and other prey, etc.)

 

So, given our biomechanics, your CoM and your hips should almost ALWAYS be facing your intended direction of travel. 

 

It is just biomechanically efficient.  It is how we humans are.

 

So, in long radius turns your CoM/hips are more "square" to the skis.

 

But in short turns, your CoM/hips face downhill which is your intended direction of travel.

 

So, necessarily, in short turns your skis turn into, past and into "squareness" with your CoM/hips.

 

But fluid/dynamic/upper-lower-separation "squareness" (instead of "counter") is actually the preferred CoM/hip orientation to skis, because it is the most strong and efficient biomechanical position given the orientation of our skeletons, muscles and joints.

 

 

P.S. I can rotate my feet while standing on a smooth surface without countering my CoM/hips.  (So, arrest me...) 


Edited by Tim Hodgson - 9/7/16 at 2:42pm
post #9 of 21

TDK, you correctly identified the problem with thinking rotary forces must always increase and always add pivoting to the skis. Like the car analogy I used when you turn the steering wheel there is an initial rotation of the steering wheel and the wheels but as you know keeping that wheel turned to that exact point requires us to maintain a specific amount of rotary force (hold the steering wheel in place) with our hands / arms. Without it the steering wheel and the wheels will turn back to a straight forward position. Even if we were just trying go straight the wheels of a car / tips of the skis encountering small variations in the road / snow surface and those small variations will cause the car / skis to deflect off line if left unchecked. I feel it is a fair statement to say we must use the appropriate amounts of active steering inputs to keep the car / skis tracking. So IMO that never ending management of corrective inputs cannot be lumped together with the static park and ride positions The Rusty mentioned. I get his intent though, if we get too rigid in any of our movements those micro adjustments we use go away and the skis stop riding fluidly over the snow.

 

I hope that makes sense and allows you to rethink the idea of rotary steering inputs always pivoting the skis. Perhaps suggesting an exercise that demonstrated this would help.

Stand on your skis without engaging any edges and simply allow gravity to pull you down the hill. The skis will begin to wobble and wiggle unless we actively apply steering inputs to control this wobbling. If we increase muscle tension to rigidly hold the skis in place, then the smooth and flowing quality we seek will disappears. Fearful skiers often do exactly this and it is the basis of the YIKES ZONE concept. I often ask students and clinic takers to do this exercise and to simply relax enough to let the skis carry them across the snow. Some small corrective movements will naturally occur but most are surprised how small these corrective movements can be if we just relax and concentrate more on balancing on the skis. From there edge and pressure skills can be added for a specific effect but by exploring and then exploiting what the skis will do naturally we can increase the efficacy in our skiing. That doesn't mean times where we add a great deal of effort do not exist, they do. All it means is great effort all the time wears us out unnecessarily.

post #10 of 21
Thread Starter 
Quote:
Originally Posted by TheRusty View Post
 

Except that would be called "park and ride".

 

I'm not sure if the negative aspects of "park and ride" can be applied on open parallel steered turns the same as for dynamic parallel carved turns.

post #11 of 21
Thread Starter 
Quote:
Originally Posted by SoftSnowGuy View Post
 

What is the biomechanical reason to keep the upper body square to the skis through out the turn?

 

In any case, what you're suggesting is against the law.  Newton's third law.  "For every action, there is an equal and opposite reaction."  You can only turn the feet if the upper body is anchored (which it can't be while skiing) or turning the other way in proportion to the relative mass of each part--feet & skis vs. upper body.

 

Exactly. So we agree there cannot be any leg rotary if we stay square to the skis through out the turn?

post #12 of 21
Thread Starter 
Quote:
Originally Posted by E350 View Post
 

SoftSnowGuy:  You can read the entire thread here:

 

http://www.epicski.com/t/147200/help-with-counter

 

But what I came away with from that thread (with a little embellishment of my own from what I teach students) is that humans are forward-facing predators.  Meaning that our eyes are in front, and our hips, knees and toes face forward because we are made to chase and catch things rather than eyes-on-the-sides-of-our-head designed to run away from things that are trying to catch us (like horses, and other prey, etc.)

 

So, given our biomechanics, your CoM and your hips should almost ALWAYS be facing your intended direction of travel. 

 

It is just biomechanically efficient.  It is how we humans are.

 

So, in long radius turns your CoM/hips are more "square" to the skis.

 

But in short turns, your CoM/hips face downhill which is your intended direction of travel.

 

So, necessarily, in short turns your skis turn into, past and into "squareness" with your CoM/hips.

 

But fluid/dynamic/upper-lower-separation "squareness" (instead of "counter") is actually the preferred orientation to skis, because it is the most strong and efficient biomechanical position given the orientation of our skeletons, muscles and joints.

 

 

P.S. I can rotate my feet while standing on a smooth surface without countering my CoM/hips.  (So, arrest me...) 

 

You are saying that in longer turns we stay more square to the skis while in short turns we turn our legs under a stable upper body. This is in essence what is common standards and in line with physics. When making short turns we create and use and fuel off of momentum and friction created by rotating our legs from side to side. Note that there is a limit as to how much we can rotate back and forth so that dictates for how long we can apply, or let the feet rotate underneath us. There is a wind up and a release mechanism at work. However, in longer turns this does not hold true. Even if we ever so gently turned our legs not to reach max rotation before the end of the turn we have no momentum to work against or with. So how do we apply continuous rotation in longer turns while staying almost square through out the whole turn then?

post #13 of 21
Quote:
Originally Posted by tdk6 View Post
 

 

Exactly. So we agree there cannot be any leg rotary if we stay square to the skis through out the turn?​

TDK, Steering efforts that produce pivots need to be much greater once the ski edges are engaged and that strong edge platform is established. This means that when we do not apply that additional effort (torque) the net effect will not be a pivoting of the skis. You can still use those steering efforts to close the radius of the turn though. Most because the pressure being applied to the tip will increase as those forces are being applied. Some suggest this lessens pressure on the tail and this causes the tails to break loose but if applied judiciously that does not occur. Hope that makes sense...

post #14 of 21
Quote:
Originally Posted by tdk6 View Post
 

 

So how do we apply continuous rotation in longer turns while staying almost square through out the whole turn then?


I don't think I think and don't think I said that we need "apply continuous (leg) Rotation" in longer turns.

 

Because I have over-emphasized carving in my long radius turns, I apply continuous Edging in longer turns, and in a somewhat uphill end of the turn, I let the skis edge uphill while my body/hips have slowly (rotated?) downhill toward the start of the intended turn in the other direction.

 

I do know, but don't do, and want to practice a continuous dynamic movement of joints during all turns.  This is what TheRusty said which I copied to my instructor notes file (you're in there too):

 

"There's a yooge difference between letting the skis turn the legs underneath the hips, slightly resisting that turning force in the hips (or feet), slightly adding to that turning force (aka waist steering or in the feet) and turning the legs/feet to force the skis to skid. All of these variations involve legs turning underneath the hips and all methods can be used to steer a turn (although I would have to argue that in order to steer when there is no intentional control of leg rotation beyond what the ski is causing, one must use control of edge angle or ski bend to affect direction change beyond that dictated by the shape of the sidecut).

 

Regardless of the technique used, the length of the turn is irrelevant. In general, the longer the turn is the more subtle the movement needs to be in order to not run out or range of movement before the turn is over. In general we strive to make virtually continuous movements of body parts with joints only stopping movement to change direction (e.g. of rotation)."

 

Anyway, my conclusion from reading here about a month or so, thanks to MrGolfAnalogy is that "Counter" in my skiing is more often a RESULT of keeping the CoM/hips oriented in the intended direction of travel which, with keeping upper/lower body separation, means that the arcing of the skis will passively create a countered position of the legs to the CoM/hips.

 

But this comes completely from my memory/visualization.  I have so much stuff I want to practice and self-guide experiment with this season.  So, if I am wrong, I have no pride of authorship, just tell me I am wrong.  Or refine it.  I just want to get it right for my personal skiing and so I can convey it right to my students.

post #15 of 21
Thread Starter 
Quote:
Originally Posted by justanotherskipro View Post
 

TDK, you correctly identified the problem with thinking rotary forces must always increase and always add pivoting to the skis. Like the car analogy I used when you turn the steering wheel there is an initial rotation of the steering wheel and the wheels but as you know keeping that wheel turned to that exact point requires us to maintain a specific amount of rotary force (hold the steering wheel in place) with our hands / arms. Without it the steering wheel and the wheels will turn back to a straight forward position. Even if we were just trying go straight the wheels of a car / tips of the skis encountering small variations in the road / snow surface and those small variations will cause the car / skis to deflect off line if left unchecked. I feel it is a fair statement to say we must use the appropriate amounts of active steering inputs to keep the car / skis tracking. So IMO that never ending management of corrective inputs cannot be lumped together with the static park and ride positions The Rusty mentioned. I get his intent though, if we get too rigid in any of our movements those micro adjustments we use go away and the skis stop riding fluidly over the snow.

 

I hope that makes sense and allows you to rethink the idea of rotary steering inputs always pivoting the skis. Perhaps suggesting an exercise that demonstrated this would help.

Stand on your skis without engaging any edges and simply allow gravity to pull you down the hill. The skis will begin to wobble and wiggle unless we actively apply steering inputs to control this wobbling. If we increase muscle tension to rigidly hold the skis in place, then the smooth and flowing quality we seek will disappears. Fearful skiers often do exactly this and it is the basis of the YIKES ZONE concept. I often ask students and clinic takers to do this exercise and to simply relax enough to let the skis carry them across the snow. Some small corrective movements will naturally occur but most are surprised how small these corrective movements can be if we just relax and concentrate more on balancing on the skis. From there edge and pressure skills can be added for a specific effect but by exploring and then exploiting what the skis will do naturally we can increase the efficacy in our skiing. That doesn't mean times where we add a great deal of effort do not exist, they do. All it means is great effort all the time wears us out unnecessarily.

 

I would like to talk a bit more about the car analogy you so kindly brought up. I would like to propose that the open steered parallel turn is more in the vein of rally car driving while the dynamic carved turn is more in the vein of F1. Or lets say dirt over asphalt. Its because of over-steering and drifting. In a corner we steer the car more with the throttle and the pendulum effect than with the steering wheel. Just watched a bunch of rally car technique videos and it is surprisingly similar to steering with skis. Instead of a throttle we adjust edge angles and body positions. When done properly we can hold onto a drift on dirt or snow with a rally car the exact same we do in an open parallel steered turn. Not touching the steering wheel or the throttle. Minimum attack angle. Effortless. In control. I call it passive steering even though there are lots of things going on. Just not any gross movements needed.

post #16 of 21
Thread Starter 
Quote:
Originally Posted by Kneale Brownson View Post

The rotational effort of steering does not have to involve displacing the toes more and more from their alignment with the body.. It can just become a steady steering pressure.

 

But against what do you rotate? What's your anchor or your counter rotation?

post #17 of 21

OK, I will bite.  Since being here I have learned more about CoM and gravity.  But a lot more about CoM and centrifugal force in a turn.  You don't need to rotate only around your CoM vis a vis gravity.  You should also be able to rotate your skis around the CoM caused by centrifugal force.  If this theory is correct, then a counter rotation of the CoM would not be necessary.  Your CoM should be able to be stationary while you rotate/steer your feet (one or both of which will at the same time be your BoS) by rotating against centrifugal force.

 

To All:  I have never taken a physics course, so consider at your own risk.  And no need to be gentle if I am wrong as long as you are right.  (Dang, it's 3:30 am in Finland, right now...)


Edited by Tim Hodgson - 9/7/16 at 5:45pm
post #18 of 21

TDK, pure counter rotation is an internal muscle act. A great example is how a cat will spin in the air when dropped on their back, this spinning in the air lets them land on their feet. We can do similar things when the skis are not strongly engaged with the snow. But far too often a small but important part of this type of movement gets overlooked. It has to do with mass and overcoming inertia. Without getting too nerdy one basic idea is that an object with a greater the mass will require more force to accelerate it (make it move). The torso being more massive than the feet and skis means moving the feet takes less effort (force). The more massive torso that is not moved by that same amount of force thus can serve as an anchor. At least when the skis are not engaged.

 

Beyond that when we establish an edge platform those reaction forces that turn the ski would also turn the body if we don't flex and turn the legs and feet. It's another example of how our muscles and joints can be used to absorb force. In the counter thread I described absorbing a landing as a special quality we possess. We also possess the ability to add additional force  

during that landing. Something we do regularly on a trampoline to gain altitude on the next bounce. Same is true as the skis are turning, we can add rotary force and hasten the turn, or pivot the skis if that is our intent. So while some folks talk about "passive" steering, I believe that is an active thing because the legs are purposely turning faster than the torso. Maybe not as actively as when we pivot the skis but active enough to keep the feet and legs following the skis and if we choose, the torso following it's separate path.


Edited by justanotherskipro - 9/7/16 at 10:49pm
post #19 of 21
Thread Starter 
Quote:
Originally Posted by justanotherskipro View Post
 

TDK, pure counter rotation is an internal muscle act. A great example is how a cat will spin in the air when dropped on their back, this spinning in the air lets them land on their feet. We can do similar things when the skis are not strongly engaged with the snow. But far too often a small but important part of this type of movement gets overlooked. It has to do with mass and overcoming inertia. Without getting too nerdy one basic idea is that an object with a greater the mass will require more force to accelerate it (make it move). The torso being more massive than the feet and skis means moving the feet takes less effort (force). The more massive torso that is not moved by that same amount of force thus can serve as an anchor. At least when the skis are not engaged.

 

Beyond that when we establish an edge platform those reaction forces that turn the ski would also turn the body if we don't flex and turn the legs and feet. It's another example of how our muscles and joints can be used to absorb force. In the counter thread I described absorbing a landing as a special quality we possess. We also possess the ability to add additional force  

during that landing. Something we do regularly on a trampoline to gain altitude on the next bounce. Same is true as the skis are turning, we can add rotary force and hasten the turn, or pivot the skis if that is our intent. So while some folks talk about "passive" steering, I believe that is an active thing because the legs are purposely turning faster than the torso. Maybe not as actively as when we pivot the skis but active enough to keep the feet and legs following the skis and if we choose, the torso following it's separate path.

 

What exactly do you mean by "legs are purposely turning faster than the torso"? If we stay completely square to our skis we are turning just as much with the torso as with the legs. Even if we used a bit of upper body counter the difference would not be significant in a 180deg turn. So we cannot be rotating our legs underneath our torso to steer the skis through the turn since our torso is rotating at the same rate. That is not what is turning the skis.

 

How about this. The skis are turning because they are brushing over the snow at an attack angle greater than cero with their edges engaged causing friction. The forward momentum, the skis edge tune, the ski shape, the ski flex, the edge angle, the pitch of the slope, the snow surface condition, our fore/aft balance, our boot placement, our alignment, our cuff flex, our upper body counter, our angulation, our arms, our concentration, our vision etc. are all part of "steering" us through an open parallel turn. That is one element of the open parallel turn. Another element would be how to initiate the attack angle. Was that the final word on steering :rolleyes

 

 

And here is the cat-flip:

post #20 of 21
Thread Starter 
Quote:
Originally Posted by E350 View Post
 

OK, I will bite.  Since being here I have learned more about CoM and gravity.  But a lot more about CoM and centrifugal force in a turn.  You don't need to rotate only around your CoM vis a vis gravity.  You should also be able to rotate your skis around the CoM caused by centrifugal force.  If this theory is correct, then a counter rotation of the CoM would not be necessary.  Your CoM should be able to be stationary while you rotate/steer your feet (one or both of which will at the same time be your BoS) by rotating against centrifugal force.

 

To All:  I have never taken a physics course, so consider at your own risk.  And no need to be gentle if I am wrong as long as you are right.  (Dang, it's 3:30 am in Finland, right now...)

 

Not sure about this....

post #21 of 21
oops...
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