or Connect
New Posts  All Forums:Forum Nav:

Tipping = Femure Rotation

post #1 of 32
Thread Starter 

True or falce?

post #2 of 32
Quote:
Originally Posted by tdk6 View Post

True or falce?



true

post #3 of 32

That's the preferred way to do it.  Of course you could tip via falling into the turn with no angulation and no femur rotation, but I would recommend against that; it's a pretty risky way to ski.

post #4 of 32
Thread Starter 

Ghost, angulation = femure rotation? And how do you fall into the turn?

post #5 of 32
Quote:
Originally Posted by tdk6 View Post

Ghost, angulation = femure rotation? And how do you fall into the turn?



No, angulation does not equal femur rotation.  (although some might call it knee angulation).  I'm just trying to paint a clear picture of how you could do it.

 

You can turn so long as the skis are tipped.  If the skis are tipped to say 45 degrees, then the knees are at a 45 degree angle to the slope too.  You COULD line up your knees hips head and upper body in a plane tipped to 45 degrees with no femur rotation and and turn.  You could initiate that turn by tilting your head and upper body to the inside and hope that the tipping and turning would catch up to your falling.  Not something I would recommend.

post #6 of 32

I'm guessing there is a hidden point to this question.

 

Femur rotation can accompany tipping or twisting, which are not that same. A skier can tip without femur rotation via inclination.

post #7 of 32
Quote:
Originally Posted by skiatansky View Post

I'm guessing there is a hidden point to this question.

I think it might have something to do with how far you can move your knees laterally through femur rotation in the hip socket without rotating your feet (a fair bit with the outside knee, not so far with the inside knee).

post #8 of 32

You can tip the skis on edge with simple ab/adduction of the hip sockets using no hip rotation. Lift one hip up and you will tip the skis onto their corresponding edges by recruiting the opposite side abductor. You can do this without "falling" into the turn, in fact, it can be a very controlled and progressive movement. Usually though, there is varying degrees of hip rotation associated with our edging movements, whether we are focusing on tipping the feet or moving our hips into the turn or both simultaneously. I like to think of this hip movement as serving a supporting role in our skiing, but I think it is good to also isolate and flesh out this movement, to really understand the role it plays on our skiing.

 

post #9 of 32

And just to further muddy the waters, You can rotate your femurs without tipping. as well as get a tip without teaching femur rotation.

 

I'm curious tdk6, what prompts the question?  Because so much of skiing is situational a broad true or false question and/or answer is likely to be at best misleading, particularly when we can assign a value judgment to either question or answer. (is tipping bad or good?, how about femur rotation? must make preferred skill look good.)

post #10 of 32

It seems to me that both tipping the foot and twisting the foot involve femur rotation.  The difference seems to be in what is happening lower down in the leg and foot. 

In tipping inward, I seem to move my knee towards the other knee while rotating the femur.  There is minimum lateral movement of the foot. The ankle tips as well.  Increased big toe side pressure.

In twisting, the knee doesn't seem to move inward as much and the femur is rotating more.  The foot moves laterally to point inwards. Minimum big toe side pressure.

 

Net, is femur rotation the defining movement of tipping vs twisting?

post #11 of 32

If by "tipping", you mean inversion/eversion of the foot, then yes.  Femoral rotation is a side effect of that movement.  However, you can (and should) counteract that rotation by turning your hips in the opposite direction (hence the term "counteracting").  Proper counteracting offsets the rotation from tipping so that the net effect is roughly zero. 

 

It should also be pointed out that rotation from tipping is completely passive.  Since there is no active twisting accompanying the tipping, there is no undue torque on the knees.  Skiers who use tipping may look as though they might be using "knee angulation" or "knee driving", but they are instead using movements that are not destructive to the knees.

post #12 of 32
Thread Starter 

No hidden points folks. Just interested in how we tip our feet in relationship to femure rotation.

post #13 of 32
Quote:
Originally Posted by geoffda View Post

If by "tipping", you mean inversion/eversion of the foot, then yes.  Femoral rotation is a side effect of that movement.  However, you can (and should) counteract that rotation by turning your hips in the opposite direction (hence the term "counteracting").  Proper counteracting offsets the rotation from tipping so that the net effect is roughly zero. 

 

It should also be pointed out that rotation from tipping is completely passive.  Since there is no active twisting accompanying the tipping, there is no undue torque on the knees.  Skiers who use tipping may look as though they might be using "knee angulation" or "knee driving", but they are instead using movements that are not destructive to the knees.


Yup, I think tipping is the inversion/eversion of the foot and agree that femoral rotation is a side effect.  Not so clear is this hip counteracting.

Lets say I am inverting my left foot (Lord, I hope that means tipping it inward on my big toe side).  The femur rotates to the right when I do that.

 

Now which way should I move my hips?
 

 

post #14 of 32

TDK, per your original question  "Tipping = femur rotation"

 

I am assuming you mean tipping the skis and not the whole body as in banking.

 

I would say FALSE.

 

Because reversing the equation is false  "femur rotation not = tipping"

You can rotate the femurs all day without tipping the feet.  Get on BB's bar stools (I made a couple of swivel platforms instead).

Independent leg rotation - yes sir!  Under a stable upper body - yup!  Tipping - nope.

 

However, as Geoffda says, hard to angulate the foot and knee without some femur rotation.  And as RicB says, you can tip/angulate the femur relative to the hips without femur rotation.

 

Now while skiing, there's a whole party going on....

post #15 of 32
Quote:
Now which way should I move my hips?

Depends -- which way do you want to move your torso?  rolleyes.gif

 

If you just tip your legs to the right, the tendency will be for your hips to also rotate to the right (clockwise if looking top-down).

 

If you're trying to make short-radius ski turns, you'll probably find it is easier if you either don't allow that rotation to happen, or 'counter-rotate' your hips to the left (counterclockwise if looking top-down).  In motion, the result would be that your hips and upper body follow a more direct path down the hill than the skis do.

 

But you don't have to do that.  In long-radius turns, usually people stay more square with the skis, although there's usually at least a little bit of counter.  It really depends on where you want your balance point to be in the turn, and how much you want to angulate vs. inclinate.

 

Although "falling into the turn" was bashed above, it's possible to make controlled turns with quite a lot of inclination.  Even WC racers will occasionally use some whole-body tipping on top of angulation, depending on turn shape and speed.

post #16 of 32

^^^^^^ Yes, we find inclination in a lot of skiing, but the risks of using inclination rather than angulation should be well understood.  First, with inclination you are "balanced" against the forces of the turn rather than being truly balanced over your ski edges.  This is all fine and dandy until your "platform" (the snow below your skis) disappears - any unexpected crud, bumps, ice, etc. and you lose the pressure against the base of the ski and you will at least bobble if not fall outright. 

 

Inclination can also often lead to some bad habits like getting too committed to the inside ski and leaning into the hill.  Both of these situations make it much more difficult to cleanly link your turns.  You often see skiers who get their edge angles mostly through inclination having a more difficult time skiing steeper runs - you can just see them getting stuck in their transitions and hunting for a way to link to the next turn.

 

I believe that it is beneficial for most recreational skiers to work on total elimination of actively using inclination in their turns.  Why do I say "total" elimination?  Because even with that goal in mind they won't actually get rid of all of it, but they may feel that they are.

post #17 of 32

 

Quote:
First, with inclination you are "balanced" against the forces of the turn rather than being truly balanced over your ski edges.  This is all fine and dandy until your "platform" (the snow below your skis) disappears - any unexpected crud, bumps, ice, etc. and you lose the pressure against the base of the ski and you will at least bobble if not fall outright.

 

I agree that, for performance reasons, you usually want to prefer angulation to inclination (and you outlined many good reasons why).  But this statement doesn't make a whole lot of sense.

 

You always have to "balance against the forces of the turn", whether you're angulated or inclinated.  If the turn forces were unbalanced, they would exert a torque on you that would either push you to the inside or outside.  In any parallel turn where your COM is inside your skis, you will "bobble if not fall outright" if your skis are suddenly deflected or lose contact with the snow, because you're not in a statically balanced position.

 

Now... what might be the case is that it's significantly easier to recover when you're mostly angulated rather than mostly inclinated.  But if you don't do something to recover, you'll fall (or at least not go where you want to) either way.

post #18 of 32

I agree with your clarification.  Of course it is possible to completely balance over the ski edges through counterbalancing of the upper body in slower turns.  As turns become faster and more powerful and your CoM is inside the turn arc then of course there are some turn forces being "handled" through some inclination and balancing against the snow pressure - that's why I said that most skiers rarely get rid of all of it.  I just feel that you will always be in a much better position to handle whatever the slope dishes out if you aggressively incorporate angulation into your skiing.  Recreational skiers naturally tend to inclinate rather than angulate - I see this with my kids and some friends.  For most skiers angulation requires skiing education to be achieved.

post #19 of 32

Good thread! 

 

Once again, I think it comes down to a very dynamic mixture of the two.  Today was crust in the a.m. and slush in the pm. In the am you  had to angulate a little or you would slide sideways down the hill.  In the afternoon you would've high-sided on pile of slush with that same technique.  Instead my students and I were banking off the slush piles like motocross berms.  It comes down to which is more efficient, fun, fast or controlled and most of all safe for that particular turn?

 

Now back to femur rotation.  Is it a side effect of tipping or is it needed to tip initially?  I hear a lot of mention of femur rotation, but rarely hear more than, "we have to rotate our femurs" and doing the chubby checker dance.  I understand the importance of being able to do that, but I'm still trying to figure out how it relates to the initial tipping moves (for me it's a side-effect). I Should I think of it as twisting the edges on the sides of my skis into the side of the hill vs. pushing down on the edges on the bottom of my skis onto the hill?  When I envision twisting the sides into the hill I instantly feel core and hip tension, perhaps similar to what Mattias was saying earlier about the hips going the other way (which by the way gave me the same feeling). 

 

Feel free to chime - that's the progression I'm learning. 

post #20 of 32

Femur rotation on an inclined slope can do so many things. Even if we don't lean, or angulate. Tip, or un-tip the skis, Pivot them, or even cause leg flexion / extension as the skis change the direction they face. So yes rotating the femurs can cause tipping but it's important to understand that it's effect is not limited to tipping. As an example think about pivot slips, skiing into and out of a countered stance, and even the dual paths theories without femur rotation and the subsequent leg steering it can produce. So IMO it's hard to offer the simple equation t=fr as more than a small part of the story.

 

 

post #21 of 32

I was inquiring more specifically as to how rotating the femur helps in the INITIAL tipping movements.  I'm well aware of the importance of rotating the femur after I tip, while pivoting, etc.

 

post #22 of 32

It's not that simple Crud. A long axis rotation of the femur can have a variety of results and depends on so many other factors like knee flex, etc...

post #23 of 32

I hear ya.  I like how you mentioned knee flex, though.  I was playing with that while skiing slowly today and found the knee flex to be my key to long axis rotational success!  (good verbage) Without it I never really hooked-up.  When skiing fast I don't think about it, it happens. 

post #24 of 32
Quote:
Originally Posted by tdk6 View Post

True or falce?


Outer or inner leg? Since inner leg is an obvious yes, then I must assume you refer to outer leg?

My answer is No.
But that doesn't mean that you can't tip by femure rotation (in this case = knee drive).
post #25 of 32
Thread Starter 
Quote:
Originally Posted by Carl R View Post



Quote:
Originally Posted by tdk6 View Post

True or falce?




Outer or inner leg? Since inner leg is an obvious yes, then I must assume you refer to outer leg?

My answer is No.
But that doesn't mean that you can't tip by femure rotation (in this case = knee drive).



If you want to maintain parallel shafts you cant just tip the inside foot can you?

 

Here is a frame capture I posted in annother thead. What is going on in your opinion?

 

K2 001.jpg

 

post #26 of 32
Actually I've found that I can. As strange as it sounds, if I just tip my inner ski (and let the hips follow the direction sideways) everything just magically turns out perfect.
I dunno if I can describe it better. Try it in front of a mirror.

Regarding your picture there are too much going on there. I would really like to see the video. It might be that he's using knee drive tipping but it may well be the angle of the camera combined with a very high c, being late in the gate, along with "medvridning" (rotation) from the gate bashing. It's impossible to tell from a still image.
post #27 of 32
Thread Starter 

CarlR, if you sit in your office chair with both feet firmly on the floor pointing forwards as are your femures and you tip your left foot onto its LTE your left knee should be moving to your left. Your right leg and knee should still be pointing straight forwards. If you are able to isolate this movement then you should realize that tipping your inside foot does not automatically tip your outside foot. From a muscle function perspective. This should be no problem because we are used to using both feet as independent limbs. Not like our eyes that work in a pair. The "magic" you are refering to is you not being able or wanting to find out what really happens.

 

The pickture.... whats going on in the pickture? 

post #28 of 32

Yes, necessary to instill enough counter to keep your belt buckle aimed down the fall line as your tipped skis drive back and forth across the hill, in and out of counter...

post #29 of 32
Thread Starter 
Quote:
Originally Posted by CHRISfromRI View Post

Yes, necessary to instill enough counter to keep your belt buckle aimed down the fall line as your tipped skis drive back and forth across the hill, in and out of counter...



Exactly, and what is that position called in the high c? And more definitions and terms to describe that position and what happens as a consequence?

 

post #30 of 32
Quote:
Originally Posted by tdk6 View Post

CarlR, if you sit in your office chair with both feet firmly on the floor pointing forwards as are your femures and you tip your left foot onto its LTE your left knee should be moving to your left. Your right leg and knee should still be pointing straight forwards. If you are able to isolate this movement then you should realize that tipping your inside foot does not automatically tip your outside foot. From a muscle function perspective. This should be no problem because we are used to using both feet as independent limbs. Not like our eyes that work in a pair. The "magic" you are refering to is you not being able or wanting to find out what really happens.


You are describing a different motion.

If you stand up tall and move your weight to one leg, and lift the other leg straight out to your side. Do you consider that movement femure rotation?


Quote:
Originally Posted by tdk6 View Post

The pickture.... whats going on in the pickture? 

I told you, I don't know. It's impossible to tell from a single frame. biggrin.gif
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Ski Instruction & Coaching