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Flexion/Extension... in that order

post #1 of 21
Thread Starter 
Rusty asked if I had anything to say regarding a certain subject in another thread, and I said I'd start a new piece... but I don't feel like writing a Mellville-esque tome on the finer points of flexion/extension. So I'll start with a question, and hope that some sort of epiphany (for someone. anyone.) arises from the ensuing discussion. Please bear in mind that I have at best a fledgeling understanding of what's going on here, so this may help me out more than anyone.

In Ski Professor's post, he showed us a picture (montage) of a very nice right turn. I paid particular attention to his outside leg. At the top of the turn, the outside leg was long. As the turn progressed, and forces began to show themselves to the skier, the outside leg gradually shortened until, at the end of the turn, it was nicely flexed and ready to "uncoil", so to speak. (Uncoil might be an inaccurate way to describe it, but I had writer's block for 5 minutes and decided it was time to move on.)

So my question is this...

What if the skier flip-flopped this process? What if we used FLEXION to help initiate and control the turn, and EXTENDED to gain edge-purchase and exit the turn?

If it helps, the idea in the clinic was to resist centrifugal force by extending or "giving back" into the sliding surface, so that by the time the turn was finished, we were already extended and ready to 1) Pass through neutral, 2)move with the skis, and 3)Get super frustrated because we weren't doing it right! On the rare occasion that I did "get it", I felt an effortless entrance into the next turn, and fantastic control in any condition, particularly in the bumps. I was better at it going slow on green runs because I was able to stay over the skis for the most part. I haven't solidified it going fast because the difference in flexion/extension leg-to-leg is so great.

So anyway, any thoughts from the physio-goobs? (that's one of those "terms of endearment", folks!)

Spag :

PS By the way. I'm just shy of brain dead when it comes to these fancy-dangled computer thingys. Could someone post that photo along with their response? Thanks.

[ October 07, 2003, 09:41 PM: Message edited by: Notorious Spag ]
post #2 of 21
I'm probably as exhausted as you at this hour of the night. Are you referring to the crossunder vs crossover?

Or mogul skiing?

[ October 07, 2003, 07:44 PM: Message edited by: KeeTov ]
post #3 of 21
Thread Starter 
Neither... Both.

No it's a little more involved than just those things, KeeTov, although I guess a person could go there...

The thing I noticed most (and I don't think I expressed this correctly in the first post) was that when flexing at the top of the turn, my skeleton did something to my skis that I didn't expect... It tipped them up on their edges and gave me a very solid feel as they turned. My thought was that as I flexed, my femur also rotated inward, (outside leg focus) my knee bent and gave me a strong sort of "lever" with which to work the ski. I found I could add rotation (leg) and edging in pretty much any ratio I wished. My only other concern was to keep my inside leg active so that it didn't get left out in the cold or get in my way. It was awesome.

So I guess my answer is that rather than steer this toward what the legs do in relation to the upper body (X-over, X-under), How about what flexion/extension does to the skis, and our alignment over them when we flex early and extend late? (I'm hoping this makes sense. I wish I had a stronger understanding of the concept so that I could help out. Physically, I'm close, but intellectually I think I need something like this to clear things up! Please "bear" with me. Pun intended.)

Spag :
post #4 of 21
We need to get Robin out of hibernation because for a couple of days after the Edwin Terrell (sp?) we explored these ideas in a series of wonderful clinics that he lead.

In essence the focus was on polarity and we concentrated on flexion/extension. We tried to flip the equation. In circumstances where one normally extended we flexed and vice versa. We did it in bumps, crud, groomed.

I guess the ski professors photo, combined with a discussion of "Canadian Style", coupled with fond memories of Robin, made the nexus.

The ski professor's photo seems to begin with a fairly long left leg and as the turn progresses flexion is built in to the progression.

Someday I'm going to try and explain my disdain for the term crossover, aka "huckover". It infers or connotes a lateral movement across a platform from a traverse. Central to my concern is the idea that the genesis for any turn is below the inside ankle. Our C.O.G may move inside a turn, however, someone once said here how is it that we move inside a turn.....it's via our feet starting the process.

I have no quarrel with the idea of retraction or avalement.

I'll call Robin in the morning and see if he can be aroused from his Bear like slumber to post. He and his former protege Spag will lead a lively topic.
post #5 of 21
Originally posted by Rusty Guy:
I have no quarrel with the idea of retraction or avalement.
post #6 of 21
Thread Starter 
Beware Robin's upcoming post and remember these easy-to-understand definitions...

"Huck-over" or "Hucking your meat" = Cross-over

"Fling-under" = Cross-under

post #7 of 21
All pejorative I might add.

Robin is a good skier, great clinician, and great writer. I hope I can get him on the computer. He was lurking here in the last day or so.
post #8 of 21
Pissed off a couple folks a couple seasons ago talking about new 'Eruo' terminology "das huckegen over" and "das underen flingigen". Funny thing was it was the 'mericans that were pissed. The Eruo trash on the ski school thought it was a hoot.

post #9 of 21
This discussion reminded me a race clinic that I took a few years ago with A.J. Kitt. He made us experiment with this concept too. But according to him in the racing he did, he liked to think about initiating the turn in a more flex position as it allows more precision to adjust the edges change and extend the feet as the pressure build up during the middle and end of the turn. The extension of the leg, allow a much more stack skeleton and result in a position that is much stronger to resist the centifugal force generate. I hope that I did not misquote him but that is how I remember it. The photo montages in Bob Barnes collection show that at the edge change the leg are more flex and that as the pressure built the outside leg is extended and the skeleton is nicely stack to resist a maximum of pressure. Just another way to see the same reality.

Bob Barnes photos

[ October 07, 2003, 11:59 PM: Message edited by: Frenchie ]
post #10 of 21
Spag, I'd guess that those really solid-feeling moments were the ones where you RELAXED the extended old outside leg to get started into the next turn and then began resisting with the new, increasingly extended, outside leg.

The slightly less effective moments were where you intentionally made a muscular action to FLEX the extended old outside leg.

I think the intentional muscular activity puts a little hiccup in the flow of the COM, just like extending the new outside leg to start a new turn does.
post #11 of 21
I'll throw two cents into this.

Think about what happens to the CM if you compress/retract/flex/whatever, as opposed to extending. Think of this in the vertical plane, as you're moving across the fall line and transitioning from one turn to the next. If you extend, you have to also physically force your CM to move down the hill into the new turn (that feeling of commitment). If you retract/flex, just by that one movement, you are moving your CM closer to your skis, and therefore, down the hill into the new turn. This way, it will seem a lot easier to get the skis to go through neutral (flat, with all 4 edges on the snow). It's simply a more efficient movement (economy of motion), than to have to extend your legs, pushing against any forces that have built up, then move your CM further to get it across the skis. Also, because your CM is closer to the skis at the beginning of the new turn, when you are on your downhill edges, you can get the skis up on a higher edge angle. If your CM was further away from the skis, it would provide too much leverage to get the skis on as much of an edge.

I hope this made sense. I have a cold and my brain is feeling kind of funky right now.
post #12 of 21
Hey, what was the subject? I got fixated on the "Great clinician", "Great writer" and GOOOOOOD? SKIER????
I have indeed been lurking...while stuccoing my house before the freeze!
I enjoyed the SkiProf montage....reeks of Canadianism! Maybe it is the CSIA Demo suit in Avalanche Red and White....we Canuck do have some stylization stigmas, I can pick out a canadian on the hill faster than Don Cherry can alienate a country!
I will try to jump in with my marginal, borderline profundity when it starts to rain outside....but will check in on the progress of this thread....but don't count on pictures of my GOOOOOD turns, Rusty! Sheeesh!
Spag...."remember to Let Go"! That was the crux.
post #13 of 21
Wouldn't focusing on extending into the turn cause you to push the skis out? I tend to think more of retraction than extension. Extension of the legs in relation to the torso seems to me to be more of a function of the ski direction, culminated by the muscle/skeletal structure defining the size.

Am I wrong, partly right, or what? I've just found I hang onto the turn past the fall line when I focus on extending.

Just a thought.
post #14 of 21

Yes, extending adds pressure to the skis, making it easier for them to be displaced more than you wanted. And if your upper body is not lined up just the way you need it to be and balanced, it could cause the now skidding skis to change the direction they are pointing, making turn entry even more difficult.
post #15 of 21
I guess it's that "when, why, how" thing that always gets me. [img]smile.gif[/img]

I can see where completely ignoring extension could lead to passive skiing, where the full range of motion is not exploited. However, as I mentioned, specifically focusing on extending has negative consequences for me (and I would suppose others).

So, how do you indirectly encourage extension?
post #16 of 21
For me,
If I was to measure my outside leg length at any point in the turn, it would not be the same length for more then maybe a couple of seconds. I am always trying to either extend and flex throughout the entire turn. Constantly in motion. Almost like riding a bike uphill. If you want to keep your bike in motion riding uphill, your legs will continue to pedal never stoping, because you would loose momentum. This flexing of one leg and extending of the other keeps your wheels moving. At no time, while riding uphill would you extend, lets say you left leg, and just leave it extended for any amount of time.You would either slow down considerably or stop.
To get your momentum up and to begin pedaling again you have to use quite a bit of power and energy. BUT, Do you find when you pedal continuosly up hill that you have a rythem going and it is much easier?
The same thing is true for skiing, I know as soon as I stop moving, my speed and turns will be compromised. If I push my leg out to extend and leave it there I tend to have a 'dead' spot, which sometimes can lead to other problems, like unlinked turns.
WHY do I extend? To keep pressure on my ski, so that I will bend it and use the sidecut. Also to help move into the direction of the new turn.
WHEN: I continuely am extending one of my legs at any given time in a turn. . I am most aware of extending my leg at the beginning of a new turn when I am switching edegesbut I feel the most pressure on the ski towards middle or bottom of the turn.

post #17 of 21
I try to think about extension as maintaining ski/snow contact through the point-em-downhill phase and then as letting my skeleton bear more of the forces building near the end of the turn.
post #18 of 21
Thread Starter 
Alaska Mike. I think anytime, a person is focusing on something like Flexing here, or extending there, they aren't skiing. They are practicing. That might be a little extreme, I guess, but it's OK to encourage someone to focus on ANY pattern of movement until they gain ownership of it. Then the focus can go away and the new skill can be utilized either passively or actively.

With regards to my original question, Robin reminded me of a key aspect of the "flex early" concept. A term that was used in the clinic was GIVING IN. As we released into the turn, we were encouraged to "just give in" and go with our skis. (I'll have to read some posts again, but somebody mentioned that my seamless "feel good" turns were probably result of relaxing the old outside leg. Kneale, I think. For me, that may be the physical result of some other trigger that I haven't put my finger on yet. Definitely the right track!) So we did. We let go of the forces that had built up on us while extending through the second half of the turn and just let ourselves sort of "collapse" into the first half of it. It felt a bit like skating, where a person uses an extension of the legs and body to accellerate, and flexion to reset for the next stride. The timing of it all created that same feel.

As far as Pushing is concerned, we make the effort to stay in such alignment that our skis do not get displaced laterally. That's already been mentioned. Extension as a means of going with the skis and joining the forces you create, not extension as a means of getting away from the skis and jumping over them to enter a turn. Things like excessive countered stance, or abrupt/explosive edge-sets can pooch the whole deal and cause you to push back instead of give back.

Anyway. Thanks for the help folks. This is just something I've been messing with for awhile and it's really helping me with my understanding of how the body moves and responds to different inputs (internal and external). Robin? You're slacking.


[ October 09, 2003, 05:42 AM: Message edited by: Notorious Spag ]
post #19 of 21

I’ve been holding back on getting involved in this thread to see just where it might go and also to make sure I understand just what Spag was about when he started it. Also, because I felt that I might end up getting a bit long winded on the subject. Still might ramble on here but I have a little time so here goes.

Flexion is bending of the joints of the lower body in such a way as to bring the feet and the center of mass closer together. Extension is straightening the joints of the lower body resulting in the feet and COM moving further apart. Flexion/extension occurs mainly in the legs and the hips/waist. Flexing results in a lessening of the pressure felt under the sole of the feet, extending results in an increase of the pressure felt under the feet. Extension results in the bones of the body being more in line with each other. This stacking of the bones results in a stronger skeletal position. Flexion puts the bones at angles to each other so we must use more muscle power to transmit force through the resulting structure. Simply put an extended stance is stronger than a flexed stance. Let me see if I can apply these observations to a ski turn. I’m going to assume a strong modern turn for the purpose of this discussion.

In a modern turn the feet and the COM follow slightly different paths. At the moment of transition the COM is directly over the feet but then the different paths of the COM and feet require that we either extend to keep ski snow contact or lose that contact and be out of control for a short time. I now need to change the direction of travel of my body. Newton tells me that to do that I must apply a force to my body to accelerate it in the new direction. Fortunately, the arced ski traveling along the snow surface is generating a force that I can use to accomplish this. I can apply a lot of force over a short time and change the direction of travel quickly (short turn) or apply less force over a longer period of time and take longer to change the direction of travel (long turns). Either way the force will tend to be greatest at the belly of the turn when I am making the greatest change of direction so to avoid fatiguing my muscles I want to be extended at that point to take advantage of skeletal strength to transmit the force. Once I have got my body moving back across the slope I no longer need the force that the skis are generating to move it about so I will allow flexion to occur so that I can manage the force generated by the ski. This flexing also moves the feet and COM closer together in such a way as to lessen the edge angle of the skis further lessening the force I feel under my feet. All this leads to that moment of transition when the COM is directly over the feet. So, I begin my turns flexed and extend to maintain snow contact and generate/transmit force then flex to manage the force and end my turns flexed.

Now, when I make a nice smooth round ski instructor turn flexion/extension tends to be a very smooth motion and paced evenly through the turn. But what if I turn up the volume a little (or a lot)? First of all I am going to be generating greater forces so I am going to want to be in the the strong extended stance as much as possible to best deal with these forces. One way to do this effectively is to create as much difference in the paths of the feet and COM as possible. Here's one way to do that. Flex smoothly through the last section of the previous turn allowing the COM to take a straighter path while skis/feet continue along the curved path. This results in my needing to get extended extremely early in the new turn to maintain ski snow contact. The other possibility is to stay long a little longer in the last turn which results in the COM moving more with the feet, I can use this greater lateral motion and a lower body edging move to create an edged ski early in the new turn and then use that edge to extend against to become long and strong for the belly of the turn. Now there is one more scenario that I have been playing with. I stay long through the end of the turn which is going to move my COM more along the path my feet are taking but I begin to move my head, shoulders, chest and upper trunk into the new turn. Then I quickly release the forces of the last turn by a combination of tipping the feet into the new turn and flexing. Because I already have a lot of mass moving into the new turn my COM is pulled into the turn along with it. This results in my having to extend to maintain ski snow contact and also establishes a early high edge angle.

To my way of thinking this last idea gives us the best of all worlds. I stay long and strong late in the turn and get long and strong early in the turn. When I release the old turn I feel catapulted into the new turn This is perhaps the most powerful way to ski i know of. One word of warning, the power generated will tend to wear one out fairly quickly, not because you are skiing inefficiently but because you are generating much more force than usual that you have to deal with.

So, there you have my take on flexion/extension at least for this morning,

post #20 of 21
I agree with your description of flexion/extension in the turns you describe. I'd reinforce a lateral focus for the flexion/extension.

If we look at skiing from falline to falline, we would be laterally extended long/strong and balanced on bent and carving skis. From the falline we relax/flex first to manage pressure as the paths of feet and Cm start to converge, and then to release Cm laterally and cross the path of the feet/skis with minimal conflict thru transition. After edge change, lateral extension creates pressure as needed to carve top of turn as those paths diverge to the falline where we are again long/strong and ready to flow thru the next cycle.

Way fun! [img]graemlins/thumbsup.gif[/img]
post #21 of 21
I havn't read the posts you were all referring to and in all honesty I didn't read all these posts. But I'm sure they're good.

I just find keeping things simple is nice. Keep your torso quiet and make it feel like it is equidistant to the snow at all times, maintain contact with the snow and in true Austrian fashion "let ze legs feeeel ze snow". The movement we are talking about is between the ankles and the hips, just let them be shock absorbers and enjoy the ride. Lateral movement of the knees will sort out the rest on most runs (exceptions withstanding). On bumps? Just do it quicker (hahaha ).
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