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# Physics and Ski Technique - Page 4

You are onto it L&AirC.

Read the thread. Jamt & Bob explain that resistance is necessary for the fulcrum mechanism to work. The barstools always provide this resistance, but in certain instances like the times your skis are flat and pointing straight down the fall line it may not exist. Some will point to this and say it therefore never works...

Yes, there is that small but oh-so-important slide fore-aft of each foot.  The bar stool model is not perfect.

It will work on the kitchen floor if your feet are in slippery socks.  Your feet need to be able to easily slide/pivot on the floor, but they also need to grip the floor a little too.  You move the feet against each other, making use of the slight resistance of friction/grip on the floor.

On slippery snow you'll need just a wee bit of edging to achieve the same small amount of ski-snow grip as on the kitchen floor.  Trail and error provides a feel for doing this.

If you are persistent, you can also get that fore-aft thing going on the kitchen floor where the uphill foot is farther uphill than the other foot.  A mirror helps.

Yes, the barstool analogy is accurate as far as describing the movements and the mechanism of "independent leg rotation" (ILS), but like most analogies it is not perfect, as it does not always, entirely, describe the exact situation of skis on slippery snow.

Many instructors like to do things like standing with both skis across a ski pole lying on the snow directly beneath their boots in order to introduce the concept, movements, and sensations of Independent Leg Rotation. It works very well, too, but few instructors I've asked can explain why the ski pole is necessary. Most assume that it reduces the friction between the skis and the snow--which it does--but that is not the correct answer. After all, when skis are flat on the snow, there is very little resistance--certainly less friction than bare feet have on a carpet, and really, the rotator muscles that turn the femurs are more than powerful enough to overcome quite a lot of resistance. So why does it work?

The truth is that the ski pole both reduces the rotating friction of the skis and increases the fore-aft resistance, which provides the conditions under which pure Independent Leg Rotation can occur easily. The barstools, of course, do the same thing--virtually eliminating the resistance to pivoting, while at the same time completely resisting fore-aft movement (as they are fixed to the floor). But even rusty old barstools that are very difficult to turn would demonstrate the principle, perhaps even better, as their resistance would require more effort from the powerful rotator muscle groups.

But as described earlier, none of this argument should suggest that ILR is not an important movement and a critical "rotary mechanism" in skiing. It is. But it does have some limitations, and other rotary mechanisms (Upper Body Rotation, Counter-Rotation, Blocking Pole Plant), as well as purposeful manipulation of fore-aft pressure and skillful edging, remain critical to supplement pure ILR in managing the direction our skis point, and in turning them (as well as preventing them from turning) as needed.

I'm glad to see this discussion arise again. I guess that's what spring and the closing of the lifts is for. I hope everyone has had an excellent season!

Best regards,

Bob

Quote:
Originally Posted by cgeib

You are onto it L&AirC.

Read the thread. Jamt & Bob explain that resistance is necessary for the fulcrum mechanism to work. The barstools always provide this resistance, but in certain instances like the times your skis are flat and pointing straight down the fall line it may not exist. Some will point to this and say it therefore never works...

Oh no you don't!  You guys aren't sucking me in this early in the off season!  I need to at least make it through May before I start all this heavy thinking

I did read the thread as it was happening and am subscribed to it.  This past season I learned quite a bit about it and feel comfortable stating I have a better understanding of it when I originally went through this thread.  It will make good reading over the summer as I can now read it from a different view point.

I love Bob's posts but the pivot slip drill and the derivative bar stool drill need to be understood as a means to teach braquage. The pelvis rotating is in large part a function of exceeding the RoM available in the hip. The elevation differences leg to leg is not that significant beyond the idea that flatter terrain makes slipping harder. Critical edge angles being closer to near flat and less acceleration from gravity force greater precision the flatter we go terrain wise.
Quote:

Originally Posted by Bob Barnes

I hope everyone has had an excellent season!

Thanks Bob, you too.  It was great to see you in the Golden Peak Lodge last month.

Quote:
Originally Posted by justanotherskipro

I love Bob's posts but the pivot slip drill and the derivative bar stool drill need to be understood as a means to teach braquage. The pelvis rotating is in large part a function of exceeding the RoM available in the hip. The elevation differences leg to leg is not that significant beyond the idea that flatter terrain makes slipping harder. Critical edge angles being closer to near flat and less acceleration from gravity force greater precision the flatter we go terrain wise.

I'm not sure that merely translating the same concept into French adds anything to it.

The intent was to mention Joubert's work on this subject. Not simply offer a French word.
Google braquage in skiing and read about the idea.
The "myth" of the quiet upper body--busted!

zenny

...but the Truth of the disciplined upper body--reinforced!

Best regards,

Bob

Exactly, Bob! In fact, it puts the concept of "skiing into counter" into a proper context in that it makes it a little more mentally palpable...

zenny

We need barstools that can tip and will turn when you tip them.

A friend of mine discovered lazy Susan hardware that acts like a u joint. He mounted it between two pieces of plywood and bingo.
It'd be cool if skiers edge made something along those lines...I have a slope simulator on mine but a swivel feature sounds interesting.

zenny

pivot disc zenny

Hmmm, not sure that'd work on the platforms...

zenny

The idea of exactly simulating skiing has been discussed many times, many devices exist but none of them exactly match what we do while skiing. To do that we need to ski. But that's not bad news IMO. The magazine sheets on the carpet, sox on tile, skier's edge, wobble boards, and such give us an opportunity to isolate and develop a particular movement pattern. Just like we do when we do a drill on skis. Their worth is limited but still useful in our quest to groove our moves.

Quote:
Originally Posted by justanotherskipro

The idea of exactly simulating skiing has been discussed many times, many devices exist but none of them exactly match what we do while skiing. To do that we need to ski. But that's not bad news IMO. The magazine sheets on the carpet, sox on tile, skier's edge, wobble boards, and such give us an opportunity to isolate and develop a particular movement pattern. Just like we do when we do a drill on skis. Their worth is limited but still useful in our quest to groove our moves.

JASP,

Your post points out one of the things that I and I'm guessing others have sort of been hoodwinked on not fully informed.  Countless times I've been on the hill or doing dry land and heard the guru of the day use words along the lines like "...it's the same movement pattern as when we're skiing..."  Not it's close to or it is only part of.  Even a similar to would be nice.  Earlier Bob Barnes posted about Instructors not fully understanding the pivoting on the ski pole drill and explaining it wrong.

Lately I've been categorizing things like you mentioned above similar to my stretching exercises.  Most of them are positions I hope to never be in while skiing, but they do help me with my skiing.

Ken

(4/27/14)

Edit above as hoodwinked was inappropriate for the point I'm trying to make.  Hoodwink implies they were intentionally misleading and that is not the case.  It is more of a case of not being clear and verifying that there is full understanding.

Edited by L&AirC - 4/27/14 at 5:01am
Barnes always says drilling isn't skiing for this very reason. That doesn't invalidate the worth of drills and off the snow training activities though. If anything good drills are a large part of a well designed learning program.
Quote:
Originally Posted by justanotherskipro

Barnes always says drilling isn't skiing for this very reason. That doesn't invalidate the worth of drills and off the snow training activities though. If anything good drills are a large part of a well designed learning program.

At the risk of veering off topic, this becomes tricky especially with kids.  A couple times I've watch the kids I have in a seasonal program skiing with their family after class and noticed they added the drill to the way they ski.  Sometimes it is only because they like doing the drill but sometimes its because they misunderstood that it was a drill.  I try to be clear, but they are 7.

I love drills.  I probably do drills more than free runs.  The key is making sure that the student (and teacher) understand the difference between what a drill is and what a skill is.

Yup, progressions that lead the student back to incorporating a blend of skills make sense. But even at higher levels and with older students it is common to see inappropriate skill blends where a drill focus has been interpreted as some sort of final form. Eventually most move past that stage once they realize skill blends must vary as they change terrain and objectives.

Good discussion, guys. I've often said that "every exercise has something wrong with it--otherwise, it would be skiing." There clearly is a difference between "drills," which tend to exaggerate some particular movement or movement pattern, to focus on some isolated component of skill, or even to involve something that isn't even turning (for example, Pivot Slips, Side Slips, and Hockey Stops, which when done properly involve no direction change whatsoever). Drills and exercises tend to involve conscious thought to modify or direct the movement patterns. Performance (that is, "skiing") at the highest levels of which we're capable at any given moment requires shifting the conscious focus to "purpose"--to tactics, line, intent--to "what," not "how"--to outcome, not process.

But--to your point, L&AirC--many of what we may call "drills" are tactical and outcome-based, and so do allow for high levels of performance. Gate drills, rhythm change drills, jumping off bumps, "follow me," skiing tree trails, and other such "games" that kids love don't necessarily fall into the category of technique-based drills. Focusing more on the "what" than the "how," they can be "skiing," while they help develop specific skills without the students even realizing that they're being "schooled." I agree with you that, in good teaching, there are very few purely "free" runs. There is always some sort of focus, whether technical or tactical, intense or light, initiated by the instructor or by the student. "Free runs" are a lot like "not teaching."

The best lessons involve a lot of learning by doing, a lot of (focused) play, and a lot of effortless learning. Our bodies have a genius for learning, if we give them the chance and get out of their way!

But great instructors never just "play" randomly, never just throw darts and let learning happen by chance. A deep understanding of technique, cause-and-effect, and yes--physics, underlies the best teaching, even when the students just think they're "playing."

Best regards,

Bob

Jim Taylor PhD speaks about free skiing and how it's never free. Whatever we do ingrains habits and this is especially true when it comes to our mental attitudes. Practice a strong focus in training and it will translate to a strong focus in competition. That doesn't mean we need to turn practice into a death march though and as a coach finding a fun way to develop skills keeps the students involved and coming back for more. There in lies the artistic side of race coaching.

From a recreational skier's perspective fun is even more important and a ski school lesson needs to reflect this important fact. I've watched more than a few instructors use the exact same linear lesson plan and seen their students slowly lose interest because the fun factor gets lost in the process. Sadly trainers tend to encourage newer staff to follow a set progression until they gain enough experience to use the stepping stones type of lesson planning. Beyond that are the guys and gals who loosely plan their lesson content and because their experience and mastery of the subject allows them to be more spontaneous when it comes to creating an effective lesson plan. I tend to not worry about a soup to nuts lesson plan since student progress influences how far we would go during a lesson. Fun tends to be too spontaneous to plan and a rigid lesson plan tends to reduce the spontaneous nature of a student's explorations. I want them to feel free to explore at their own pace and worry less about adopting some theoretical final form. Ironically, when my students eventually allow their "inner child" to come out and play they also discover their "inner expert".

Since the topic of fun has been touched on: when myself and others are working on our personal skiing I always make sure we incorporate some "just skiing" runs in. So it's 2 drill focused or line rotation runs followed by 2 fun and/or ripper runs. Often we go all day with this cycle; 2 runs "on", 2 runs "off", rinse and repeat. A warm up run or 2 is also mandatory when Coach zenny is in charge! (you can call me Josh if you want ) Note that these cycles which I mention are not of course possible while instructing in an "official" capacity.

Sometimes all my fellow coaches want to is drill all the time and in doing so lose sight of one of the goals in skiing, which is to have fun! And when you're having fun you learn more--at least I think...chad?

zenny

guess it depends on the drill and what someone would consider "fun".  There is often a lot of benefit in teaching someone how to use a drill to gain a diversity in control and self understanding, they are 'fun", even skiing "free" is a drill, where does a person need balance on that spectrum? JASP has already eluded to it, just to add my thoughts, it is more than developing strong focus, it is generating that balance in how to use all types of movement, the ones generated with focus and the ones that come naturally in playful times, there is different information to get from either type.  The troubles JASP mentions in hard line lessons, protocol, etc is a good example, does the lesson move across the whole spectrum, maybe some clients need more time spent on "drilling" or maybe more from "free" skiing, finding that balance but incorporating all of it is where the joy of teaching and learning come together.

Bob stated something important and will leave him to extrapolate if he would like, effortless learning.  What are the qualities in the movement we see in others that would let you know they are in that effortless learning zone?

The sports diamond is really helpful when it comes to balancing lesson content. It is predicated on the belief that when we encounter difficulty in one "corner" shifting our focus to another "corner" allows the body and mind to self correct and thus the difficulties in that first corner are eliminated. Even if that mental break doesn't produce the self corrections, at least when we revisit that corner the student isn't as frustrated.

Quote:
Originally Posted by chad

.  What are the qualities in the movement we see in others that would let you know they are in that effortless learning zone?

No. 1: The smile.

No. 2: Movements flow together.
Quote:
Originally Posted by justanotherskipro

I love Bob's posts but the pivot slip drill and the derivative bar stool drill need to be understood as a means to teach braquage. The pelvis rotating is in large part a function of exceeding the RoM available in the hip. The elevation differences leg to leg is not that significant beyond the idea that flatter terrain makes slipping harder. Critical edge angles being closer to near flat and less acceleration from gravity force greater precision the flatter we go terrain wise.

I learned "braquage" from the former French national team member who was my first ski school director. His approach was use the flattest terrain available and get into a squat so the pelvis couldn't be employed in turning the feet out of a straight run.
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