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Skiing, the Science

post #1 of 19
Thread Starter 
In the Carving Speed Control thread, Physicsman says:
I would think that showing improvements in very specific measures like constancy of speed during the various phases of a turn, and then correlating these to techniques which have hitherto only been anecdotally favored would lift the overall level of our instruction, as well as be pretty strong ammunition in support of advanced instruction for recreational skiers.
In the thread asking him about a device to measure pressure underfoot, Physicsman says:
OTOH, using such technology to truly understand the very fine points of skiing, and remove the anecdotal, "it-feels-like-this" basis for much skiing pedagogy would be a highly worthwhile endevour (at least IMHO).
If Physicsman's proposition to scientifically measure and quantify the fine points of skiing came to pass, and it removed the anecdotal, "it feels like this" basis for much skiing pedagogy, would people learn skiing any better than they do now?
post #2 of 19
Wouldn't it still feel like this or that? I'll qualify this by saying that anything that furthers the teachers understanding should translate into better more effective teachng, which would hopefully tranfer to the student, how effective and efficient will feel.

Are emperical science and feelings exclusive of one another? I think Hanafords book "Smart Moves, why learning is not all in your head" explains and answers this. It seems to me that removing the inconsistencies of the anedotal interpretations could be a good thing. One the other hand I use what I feel as a gauge to weigh what someone else is saying. If I couldn't feel the sensations of my movements, why would I want to ski? Later, RicB.
post #3 of 19
Skiing is both art and science. How much of each, I don't know. But I really like the art side of it. The science side provides more understanding, but visually it is art and learning can occur purely by that.
post #4 of 19
You might get scientists understanding better what "it feels like this" actually means, but how would that get conveyed to the student? How would you quantify the student's understanding other than to wire him up too?

I agree with Sir Turnalot that the art remains more important than the scientific understanding.
post #5 of 19
Me too Kneale.
post #6 of 19
Make it three
post #7 of 19

The simple answer is yes and no. This discussion will (should) probably evolve into a discussion of teaching and learning styles, along with experience level.

Physicsman and I are cut from similar cloth. (He's the scientist, I'm the engineer.) We both take the scientific approach to problems. Quantifying things is something that is natural to us. It is part of our learning and teaching style. To find out the how and why, we tear apart and analyse the bits and pieces that make up the whole. Then we put them back together to see how they interact. (Now I know why I love Movement Analysis. )

At lower levels, teaching a sport is about gross motor skills. There is a lot of watch this, do this, try this, feel this. The student is trying to figure out what goes where, how do I control this, and why should I do this. This is the time when the "WOW" and "AH HA" expressions are used. There is a lot of art in teaching at this level. Guiding your students to success is tricky and you need to have the proper skills to do it.

At high levels, then you can start to get really scientific. (Look at what they use to coach Olympic atheletes.) I see the stuff that you brought up in your initial post as being used primarily on the Olymipic and Professional Levels. (At least for now, when the cost are so high.) While you can see the gross skills represented, its the minute changes that this equipment can really help with. Wiring up someone like Bode Miller and saying let it rip would give you a baseline to start with. Then you'd tweak things to see what happens. If you pressure here, just a little, do you move down the course faster? Using this stuff could help a pro identify the slight changes that give him the competitive edge.

That doesn't mean we can't use this stuff with beginners. You could wire up a beginner and move her into an efficient stance then say "Feel that? That's what you should feel when skiing." It should help a little, but I don't think it will be all that useful to start out with.

What would be fun would be to see where and when this type of stuff should be used in teaching. Sort of like figuring out when to introduce the pole plant to your students. :
post #8 of 19
One of the main things I want out of a lesson is feedback.

I have found that frequently I am not doing what I think I 'm doing. A good instructor can show me what I'm really doing vs. what I think I'm doing, and then show me how to do what I thought I was doing in the first place.

Electronics could provide real-time feedback so I could tell what I was actually doing while I was doing it.

The first thing I'm going for is a series of strain gauges under my feet with a readout inside my goggles so I can tell where my fore-aft balance is!

Then I'll go for the edge angle indicator, turn shape gauge, and the carve/skid percentage meter.

The digital fun-o-meter will be hardest to implement.
post #9 of 19
How do you quantify an unintentional heel push, a minor wedge entry or a dragging outside hand? I think it would be pretty difficult, compared to something like range monitoring. For intstance, for line intercept, you record what is there every 0.5 meters. Pretty specific and pretty quantifyable. What is a person doing every meter? Or 5 meters? Pretty difficult to quantify. Except where they are doing the same movement every turn. If you can quantify every movement that a person makes, you can make adaptive changes in their skiing. An occassional hand drag or heel push are far more difficult to effect a change.

post #10 of 19
Now, where to we hang the dashboard so we can watch the instruments as we ski?
post #11 of 19
It would help some students learn (eg physicists, engineers, science types) but would not help others.
Oh the funometer...first crack at the can how about velocity times acceleration.
post #12 of 19
Thread Starter 
I'd like to hear more about it from Physicsman. How would we go about scientifically correlating anecdotally favored techniques to specific, measureable, reliable outcomes? I would like to know that what I am teaching 1) has a scientific basis and 2) has been shown to work, instead of suffering from "recency bias" along with the entire ski world, tending to give anything new (contemporary, modern, trendy) more credence than something old (dated, traditional, old school) without regard to the quality of the science behind it.
post #13 of 19


Originally Posted by nolo
If Physicsman's proposition to scientifically measure and quantify the fine points of skiing came to pass, and it removed the anecdotal, "it feels like this" basis for much skiing pedagogy, would people learn skiing any better than they do now?
I completely believe that accurate measurement and clarity, expressed in a comprehensible language, would be wonderful for ski teaching. However, I don't see any reason (or possibility) for it to remove the anecdotal versions. I'd even say that if they were removed, and replaced with the measured, scientific description, then people would learn to ski much worse than they do now.

Ideally we keep searching to connect the objective reality of the movement patterns to the subjective interpretation. There are advantages to each, and enormous pitfalls in embracing either to a fault.
post #14 of 19
I get lots of feedback from my body. For example, I get proper edge angle and forward pressure feedback when I feel the edge start to give or I see that my arc is not getting me to where I need to be.

I think the man-made external sensors are useful for academics mostly. The forces required can be calculated but how a skier is applying the force is what the sensors could tell. The external man-made sensors could quantify the distribution of force. They could be useful for troubleshooting a particular symptom in a high level skier. However, I would much rather look at some video and use my internal sensors.

Timing systems are being used to test speed vs line with respect to radius or turn placement. And this is useful for the racer feedback, but it does not go toward skill improvement but only toward application of skills already aquired.

Interesting topic. Personally I really just want to practice skiing challenging terrain and skiing it well. Did you notice I didn't say "ski it better"? At my age it's becoming a matter of maintaining skills. Getting better - I'll let you know at the end of next year.
post #15 of 19
Thread Starter 
I confess this is a tough question for me, because while I would like to know what I am teaching would pass muster with Physicsman, and I think we should be able to quantify what good skiing is, and it would be nice to develop a scientifically validated ski teaching system, in my heart of hearts I think that skiing is a closer relation of poetry than of science. Has ballet technique been scientifically validated? If it was, would it improve the dance? Is flow, grace, and attitude something we can quantify? Please help me understand your thinking, Physicsman.
post #16 of 19
Originally Posted by sir turnalot
Interesting topic. Personally I really just want to practice skiing challenging terrain and skiing it well. Did you notice I didn't say "ski it better"? At my age it's becoming a matter of maintaining skills. Getting better - I'll let you know at the end of next year.

Don't know how old you are, Sir, but I'm 65 and my skiing improves every year. Not my stamina or strength, but my skiing. Actually, my declining physical capabilities may contribute to my developing increased efficiency.
post #17 of 19
You are older than me but I am not dirt. I say, "I'll let you know at the end of next year", because it's an ongoing experiment with me. I have said, I think, in some other posts that I am just climbing back into the saddle after many years of skiing only several times a year. Last year I skied about 40 days but broke my arm in early March. This year about 60 days. I'm still climbing into the saddle. This year, I regained much of my balance instinct which had declined over the years.

Next year will be a tell tale year. Actually I don't want to stop now, I'm at a point that I need to keep going.

By the way, a neighbor of yours, who is about my age, had a pretty good Master's Nationals.
post #18 of 19
Originally Posted by nolo
I'd like to hear more about it from Physicsman...
Good topic, but unfortunately, I have a couple of labs full of seniors who have get their projects working in the next week or they don’t graduate. In addition, in exactly the same time frame, the juniors have to get me to sign off on their project proposals for senior year or they face their own problems. Because of this bad timing, my reply to this thread is going to have to be shorter than my usual tomes. (Come to think of it, maybe that isn’t a bad thing. )

Let me start off by saying that even being the geek that I am, I agree with many of the negative comments in this thread about the limited utility of instrumentation on skiers. I certainly wouldn’t want to be instrumented when free skiing. I love the physical sensations, mountain beauty, camaraderie, etc. as much as anyone else. Even if by myself, working hard on technique, I would never want to have a heads-up display mounted on my goggles showing me all sorts of technical data streaming from multiple sensors – it would be overwhelming. In such a situation, I might want/tolerate only one sensor at a time giving me specific feedback, and then only occasionally, to supplement conventional teaching techniques. For example, if my instructor was working with me to develop larger angles, it might be awfully nice to have a simple device that gave me instantaneous feedback on my edge angles for several runs. Useful as that might be, I still would need to supplement that info by looking back at my tracks, having someone with a good pair of eyes follow me, etc. for many reasons, not the least of which is to detect other problems that one sensor would never catch. I suspect that most people feel the same.

That being said, I do think that there is a place for having instruments available to researchers, and ski instructors in positions which influence the teaching of other instructors. Rather than try to justify this abstractly, it’s probably easier to just give a couple of examples picked from recent examples right on this forum:

#1) In the thread on carving speed control ( http://forums.epicski.com/showthread.php?t=26995&page=3&pp=30 ), I brought up the issue of whether fore-aft changes in pressure changes a skier’s terminal velocity in a schuss. I suggested that it had little effect, except in a few specific cases. Obviously, this could be checked in one particular location, in one set of snow conditions by a speed trap, but if one had convenient instrumentation that recorded a skier’s instantaneous velocity, the hypothesis could be checked all over the mountain, with different skiers, in powder, etc.

Wouldn’t it be nice if these tests resulted in a paragraph in a PSIA training manual that said something to the effect, “If you encounter someone sitting on his tails, schussing a runout and risking ACL injury, you can tell him with certainty that he probably added a maximum of 0.2 mph (or whatever) to his speed.”

#2) Further down in the thread on carving speed control, I offered a hypothesis about increased snow friction at the apices of high-G turns. The increase that I discussed certainly takes place, and it sounds like it could be the dominant mechanism to explain SSH’s questions. However, whether or not it really is the dominant mechanism can’t be tested without instrumentation.

As in the previous example, wouldn’t it be nice if on-snow instrumented tests on this issue resulted in a couple of graphs in my hypothetical training manual that showed wild variations in speed through the duration of a turn for a lower level skier, and much less variation (same average speed) for someone using the higher level techniques of Nolo and Uncle Louie. Trainers at resorts throughout the US (world?) could hold up these graphs to their L-I’s in clinics and say, “This is why we are putting you the hoops!”. Those L-I’s would then convey this sense of purpose based on objective accomplishment to their recreational skiing students.

#3) Every year or so on Epic, one is guaranteed to find a thread on some aspect of carving/skarving. For example, “can one be carving with the front of the ski while the back of the ski is skarving”? Having instrumentation along the length of the ski designed to quantify deviation from a pure carve could easily provide a yes/no answer. Such data might not put more philosophical issues like “can any carve be pure” to rest, but having some technical questions answered definitively / quantitatively certainly is better than leaving all the steps in an argument up for debate.

I’m sure that anyone following this and other threads on Epic could come up with many, many more examples of half-baked, “doesn’t sound quite right” comments they have heard in clinics / lessons which could be once and for all set to rest by some simple quantitative, on-snow experimentation, and then incorporated into training materials.

As has been said many times before on Epic, one certainly shouldn’t convey even a small fraction of such technical info to lower level students, but I firmly believe that having instructors know that it’s available and knowing which parts of skiing are art and which parts are based in science can only be a good thing. As an example of the latter, I had to sit through a clinic this year where the clinician (who had obviously never taken a physics course in his life) tried to give his 10 minute long “personal interpretation” (his words) of centrifugal forces. It wasn’t the appropriate situation to step in, so I just had to bite my tongue and let it pass. I’m sure that our own students can just as easily distinguish between something that is complete BS coming from the mouth of an instructor, versus when it is a simplified version of a more complete explanation/theory. The former doesn’t do anything to help SS enrolment problems.

Gotta run,

Tom / PM

post #19 of 19
good post Weems!

It seems to me the beauty and attraction to skiing is in it's total unending motion and the sensations it gives us. I have always believed it is the instructors job to put those sensations into words with analogies and metaphores and demonstrations so that the student can imagine what those sensations might feel like then try to experience them.....but then this is my particular learning style. Think with your feet!

It's nice to read the analytical explanations that add understanding as to why I feel what I feel but.... I have never gone through a linear checklist in my mind as I was skiing. Rather I may be searching for a particular sensation during a phase of the turn that would translate to better skiing. Then in an effort to communicate with others those sensations have to be verbally communicated and therein lies the challenge for us all.

Skiing is a movie not a snap shot. In my experience too much analyzing leads to staticisity.
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