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How to correct aft position

post #1 of 13
Thread Starter 

At the last part of a turn it can easily happen that the position gets a bit aft, and in racing it can actually be desired because it can be faster (think Bode). The problem is how to get out of this position. There are basically two things you can do:

- pull the feet back

- push the feet forward

At first this may seem a bit strange, how can two opposing moves be used to accomplish the same thing?

 

Pulling the feet back will move the engagement point behind of the force vector from the body and will thus result in a balanced position.

 

By pushing the feet forward using the knee joint the stiffness of the boot in the backwards direction will result in pressure on the tail of the ski, and this will rotate the body forward and eventually result in a more forward position.

 

What is your analysis of these approaches, when is one used, and when is the other used? Is one move more natural than the other?


Edited by Jamt - 10/6/10 at 9:55am
post #2 of 13

I think you have it a bit mixed up. The reason Bode is aft has nothing to do with him trying to get forwards. He is aft because he is aft. He has requested stiffer skis to support this aft balance. But its a float thing. At apex when he is powered up with turn forces he is centered over his skis like everybody else. Byggmark is annother one with a very aft stance. It has to do with how our limbs are moving in ref to each other as we retract our legs during the transition. You are pointing out that the feet are pushed forward at the end of the turn and that the shift in balance aftwards in ref to the BoS is compensated by bending forward with the upper body. This is correct but the skis are not poweded up. They are entering the float. Back when the short skis became popular in SL everybody was struggling with their for/aft balance ending up on their back if they did not bend forwards at the waist and reaching forwards with the arms.

 

Many times you hear people say that you should be pulling your skis back. This is kind of weard because if you never push them forwards how can you be pulling them back all the time. The thing is that as you come into the transition and flex through it you lift your knees up in front. This is the same as pushing the skis forwards. Or letting them slide forwards. There are many cues for this.

 

Here is a simple graph to display a centered stance, feet pull back and feet push forwards. I did not include dropping our hips back like sitting on a chair kind of stance but that would be the extreme feet push forward move. Or would it? What is more important: the action or the outcome?

Feetpullback001.jpg

 

All things considered this is a great topic. However, you need to be more specific. For example what means: pushing your feet forwards using your knee joint? Pushing a knee joint forwards? Would that be the same as pushing the knee forwards? Be more specific. The knee jointcan perform only two actions, open and close. Other leg musles can move your knee sideways and up and down.

post #3 of 13
Quote:
Originally Posted by Jamt View Post

At the last part of a turn it can easily happen that the position gets a bit aft, and in racing it can actually be desired because it can be faster (think Bode). The problem is how to get out of this position. There are basically two things you can do:

- pull the feet back

- push the feet forward

At first this may seem a bit strange, how can two opposing moves be used to accomplish the same thing?

 

Pulling the feet back will move the engagement point behind of the force vector from the body and will thus result in a balanced position.

 

By pushing the feet forward using the knee joint the stiffness of the boot in the backwards direction will result in pressure on the tail of the ski, and this will rotate the body forward and eventually result in a more forward position.

 

What is your analysis of these approaches, when is one used, and when is the other used? Is one move more natural than the other?


Jamt,

 

1) "pull the feet back"  

 

2) "push the feet forward"  ????  how about, dorsiflex the foot, pulling the forefoot against the top of the boot which pulling the hips forward?

 

3) take the short cut, projecting the hips laterally across the feet to the inside of the next turn?

 

or a combination of all three?

 

 

post #4 of 13
Thread Starter 

I never said that he was aft becuase he wanted to come forward. The point is that if you are aft you have to do something about it.

 

I modified the picture to show what I mean.

df598346_Feetpullback001.jpg

In the rightmost the force from the snow comes further from the tail, becuase the boot is very stiff in that direction.

 

The middle picture is kind of what I was after, too pull the feet back when you have shin pressure is a very strange movement, you are basically straightening the leg at the knee joint.

If you start out with shin pressure I think the best approach is to push the feet forward.

On the other hand if you start out with a classical begginner-type aft position, with pressure on the back of the boot, and probably with quite straight stiff legs, then pulling the feet back is a much better approach.

 

My favorite clip show this a couple of time I believe, e.g. at 3.05

 

post #5 of 13
Thread Starter 



 

Quote:
Originally Posted by bud heishman View Post




Jamt,

 

1) "pull the feet back"  

 

2) "push the feet forward"  ????  how about, dorsiflex the foot, pulling the forefoot against the top of the boot which pulling the hips forward?

 

3) take the short cut, projecting the hips laterally across the feet to the inside of the next turn?

 

or a combination of all three?

 

 


Good input, I guess I missed a couple of ways to correct the balance. What you describe in 2 will not be the same as kicking the foot forward, but it will have the same effect of moving the force on the ski backwards.

 

One key I believe is that the movement is very brief, it just start a forward rotation of the body which will put it in balance later on. With some good timing it will help with entering the next turn with a forward momentum.
 

post #6 of 13
Quote:
Originally Posted by bud heishman View Post


Jamt,

 

1) "pull the feet back"  

 

2) "push the feet forward"  ????  how about, dorsiflex the foot, pulling the forefoot against the top of the boot which pulling the hips forward?

 

3) take the short cut, projecting the hips laterally across the feet to the inside of the next turn?

 

or a combination of all three?

 

 

 

The whole push/pull thing is confusing. For instance if you pull someting, its towards you. If you push something, its away from you. Or you pull yourself towards something or push away from something. So when you "pull your feet back" you are eather pulling them back from a location forward or aft. If your feet are forward and you pull them back the pulling stops once the feet are underneath you. If you keep on pulling the pulling becomes pushing. Then you are pushing your feet back. Its always the body part with less mass that is moving.

 

A pure dorsiflexion movement will pull your hips forward / push your feet backwards. Its because if you flex your ancle your upper body will tilt forwards. Its a bit inaccurate because its not just your hips that are being pulled/pushed forward. Its your entire body. But, what if your shins are pressing moderately against the boots. And the boots are buckled up firmly and they are quite stiff. Lets say Doberman 130 and -10degC. How much will this dorsiflexion movement move your hips forwards? And correct me if Im wrong but would not most of us also flex at the knees and hips if we flex our ancle? That would shift our hips back.  I think that the most bang for buck movement would be an aggressive leg extention. Pushing the feet back. That would offset our hips forwards. That would also stack our bones favorably if it was done towards apex and when forces are building up.

 

Your suggestion to move our hips laterally into the turn sounds just like the leg extention I mentioned earlier. But note that your inside foot would be bending at the knee and therefore that foot would be pushed forwards. Your hips would be pushed back. Or lets say your inside hip would be pushed back while your outside hip would be pusched forwards. Or actually its a blend of both hips and feet. And the forces reacting upon us. Depending on how much weight we put on each foot.

 

A combination of many things for sure.

 

 

post #7 of 13
Quote:
Originally Posted by Jamt View Post

I never said that he was aft becuase he wanted to come forward. The point is that if you are aft you have to do something about it.

 

I modified the picture to show what I mean.

df598346_Feetpullback001.jpg

In the rightmost the force from the snow comes further from the tail, becuase the boot is very stiff in that direction.

 

The middle picture is kind of what I was after, too pull the feet back when you have shin pressure is a very strange movement, you are basically straightening the leg at the knee joint.

If you start out with shin pressure I think the best approach is to push the feet forward.

On the other hand if you start out with a classical begginner-type aft position, with pressure on the back of the boot, and probably with quite straight stiff legs, then pulling the feet back is a much better approach.

 

My favorite clip show this a couple of time I believe, e.g. at 3.05

 



Jamt, thanks for the edit but you forgot to edit the forward stance frame (moved the order by the way so that center would be centerstance). I did that and it clearly shows that pushing the feet forwards puts you in a aft position.

 

If you look at Felix N you can see that he has massive tip lead at the gate and shortly after. Massive. His outside leg is crushing the boot sole while the inside boot remains compeltely neutral and upright. There is very little pressure on that ski.

post #8 of 13
Thread Starter 



 

Quote:
Originally Posted by tdk6 View Post





Jamt, thanks for the edit but you forgot to edit the forward stance frame (moved the order by the way so that center would be centerstance). I did that and it clearly shows that pushing the feet forwards puts you in an aft position.

 

If you look at Felix N you can see that he has massive tip lead at the gate and shortly after. Massive. His outside leg is crushing the boot sole while the inside boot remains compeltely neutral and upright. There is very little pressure on that ski.

 

Sure, pushing the feet back back puts you in an aft position, but only briefly. If properly executed it will give you forward rotating momentum into the next turn. We are talking maybe 0.05-0.1 seconds. In full speed it can hardly be seen. I think the problem is that we are discussing a dynamic event with static pictures.

 

If you stand on the living floor in a balance position and slowly tilt backwards at the hip until you have aft balance slighly in front of the heel; - what do you do to recover the balance? A natural move is to briefly move the pressure to the back of the heel until you start to rotate forward. With boots and skis you can do this much more powerfully.

 

Dolphin turns is an extreme example of what is going on. A very good drill for dynamic fore-aft balance.

 

 

This movement was a real epiphany for me when I started to use it in the slalom course. In particular when combined with a pivot.

 

Do you think Felix has greater tip lead than normal in WC? If so that would be interesting considering his performance in the WC last year.

 



 

post #9 of 13
Quote:
Originally Posted by Jamt View Post

 There are basically two things you can do:

Hmmm - Why does aft have to be corrected? Can you use your core muscles to initiate forward movement?

post #10 of 13

Or rotary for that matter rusty. My last slalom coach asked us to ski without any shin pressure and to slingshot the feet ahead of the body through the transition. We were tasked with never pressuring the tongues of the boots. More than a few eyebrows raised when we were asked that but in the end we all found no need to lever forward into the boots or break at the waist to find balance. So much for conventional wisdom. That being said the level of skiing needed to do those turns is pretty high. So knowing how to do a centered turn and a fore levered turn are skills everyone already knew. Is it a pre-requisite to the aft stance turns we were doing, IMO yes.

post #11 of 13
Quote:
Originally Posted by Jamt View Post

 

Sure, pushing the feet back back puts you in an aft position, but only briefly. If properly executed it will give you forward rotating momentum into the next turn. We are talking maybe 0.05-0.1 seconds. In full speed it can hardly be seen. I think the problem is that we are discussing a dynamic event with static pictures.

 

If you stand on the living floor in a balance position and slowly tilt backwards at the hip until you have aft balance slighly in front of the heel; - what do you do to recover the balance? A natural move is to briefly move the pressure to the back of the heel until you start to rotate forward. With boots and skis you can do this much more powerfully.

 

Dolphin turns is an extreme example of what is going on. A very good drill for dynamic fore-aft balance.

 

 

This movement was a real epiphany for me when I started to use it in the slalom course. In particular when combined with a pivot.

 

Do you think Felix has greater tip lead than normal in WC? If so that would be interesting considering his performance in the WC last year.

 



 


Im still not with you. You are saying that pushing the feet back puts you in an aft position. IMO its the other way arround. If you look at the graphs (here is the new one I somhow forgot to include in my previous posting last night) below you can clearly see that pushing your feet back shifts your CoM forwards. And pulling your feet forward shifts your CoM backwards. Here is the modified graphs:

Feetpullback002.jpg

I also do not agree with you regarding how you recover from an aft balance. IMO all balancing movements are done with the hips in the opposite direction. If I stand up on the floor and close my eyes and lean back untill Im out of balance my impulsive recovery movement is to move my hips forwards. Just as my impulsive recovery movement sideways is moving my hips in the opposite direction. Or if you look at it the other way arround I move my upper body in the direction of where Im about to fall. Not all people balance like this but I think its the most natural way. As far as Im conserned its the correct way. But I can also do it the other way arround if I put my mind to it. And maybe it is the correct way of recovering in sertain situations. Im not sure however this is one of them.

 

But in skiing recovering from an aft position is not always just for recovering our balance to neutral. It can serve other functions as well. You talk about using your boots and skis to gain a forward rotational motion of your body that you move into the next turn. You also say that its great in combination with a pivot. Our skis and boots change the way we balance in the fore aft plane since we can hang on the back of the boots momentarily and gain a forward rotational momentum of our body. Like in the dolphine turn. But that is far from a recovery move. And its very dependent on what kind of gear we are on. Lets say you are on soft short 155cm carving skis vs you are on 165cm stiff racing skis. I need to experiment with this kind of movement. Thanks for pointing it out.

 

Annother aspect of pushing our skis forward or pulling them aft is gaining speed. You are probably familiar with nordic cross country skiing technique. In the scating disipline every time we scate we gain more forwards speed. But the movemen is backwards. The movement is stand on one foot on the floor, bend your knee and jump backwards. This is a heel push off. Its what the speed scaters are dooing. And inline scaters. And alpine skiers. But it has to be thaught. Larsson is a good example. But that is my own theory.


 

post #12 of 13
Quote:
Originally Posted by Jamt View Post

 

Do you think Felix has greater tip lead than normal in WC? If so that would be interesting considering his performance in the WC last year.

  


Thanks for posting the videoclip of Felix. That is an absolute favorite of mine as well. It would have been nice to see some other skiers on the same track for comparisson. No, I dont think Felix has more tip lead than other wc racers in general. Outside ski pressure and extreme edge angles and projection into the turn all result in tip lead.
 

post #13 of 13
Thread Starter 


TDK, sorry, I meant to say that pushing the feet forward. I must be jet-lagged, I have spent the week in South America (But not on the Chilean ski-slopes unfortunately).

 

Regarding the movements.  From an outside force perspective, the only way to rotate the body forward is to move the engagement force from the snow backwards. This can be done by moving the skis backwards (pull the feet back) or by changing where on the ski the force comes (pushing feet forward, lifting toes, core movements). Pushing the foot forward is not a natural move, but IMO it works pretty well in many situation.

 

I'm sitting in the airport now so won't try the floor-exercise smile.gif

 

JASP, I think that it was after a discussion that you were inolved in that I started to experiment with this. I think you called it "kick the can". I might have misinterpreted though.

 

I miss the snow.... still 1.5 months to go here.

 

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