If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
Janne G wrote
Tell me what you see in Björndalen that differs from your video. Wow, what a great challenge. I'm looking at the front skier in the red-and-black tights and Carbon-silver boots in the first two seconds of the video skateclimbslomo.mpg which I downloaded from ftp://avari181.mt.luth.se/pub/mpeg/skidor/Technic. I'm comparing it mainly with V1 side-view video. Here's what I observe: (a) Björndalen's ankle is flexed forward a little more than mine at the instant his foot lands, and I think also flexed forward more at the end of the leg-push. (b) Björndalen plants his poling-side a little before he lands his poling-side leg, and his poling-side hand starts alongside his ear. I plant my poling-side pole simultaneous with landing my poling-side leg, and my hand starts in front of my head, so my pole starts more angled back and his starts more vertical. (c) B is extending his leg out to a bit closer to straight than mine in my V1 side-view video. Though in my V1 front-view video I'd guess I'm extending out as far as him. (d) In the pole-push, B is driving his hands down lower than mine, and then further back than mine. I think my poling motion gets closer to B in my V1 front-view video. A hypothesis is that in the side-view video, the steepness and slow snow were too much for my non-elite muscles to handle with V1, and I should have switched to single-poling "coaches" skate. Comparing my V1 front-view video with the other racers (since there's no front-view of Bjorndalen): (e) While pushing on my recovery side I'm bending my torso sideways so that my recovery-side shoulder is more over my recovery-side foot -- that's a deliberate attempt to maximize my side-to-side weight shift. (f) But sometimes I also see what looks like some bending of my torso backward which Andrew mentions -- which is not deliberate and for which I cannot imagine a positive benefit. (I'm thinking instead that when I swing my shoulders over to the recovery-side, I need to keep them lower longer, and focus more on moving fully sideways first, rather than get diverted into rising upward too early.) (g) The elite racer's heads are much more stable than mine in the V1 front-view video. Though I think my head-stability in the other videos (notably the Legs-only front view) is better. My response to those observations is that I'd like to make all of those difference points to become less different -- except maybe (e). What do you see as different? Ken __________________________________________ Janne G wrote Ken take a look at the skateclimbslomo.avi at my site and compare especially Ole-Einar Björndalen that are skating at the far side from the camera. Tell me what you se that differ from your video. This was intresting, so intresting that i whanted to go out with the video myself and try it, but then the thermometer was hovering around +6C, not my favorite snowcondition. Janne G |
Ads |
#12
|
|||
|
|||
Ken Roberts wrote:
Janne G wrote Tell me what you see in Björndalen that differs from your video. Wow, what a great challenge. I'm looking at the front skier in the red-and-black tights and Carbon-silver boots in the first two seconds of the video skateclimbslomo.mpg which I downloaded from ftp://avari181.mt.luth.se/pub/mpeg/skidor/Technic. I'm comparing it mainly with V1 side-view video. Here's what I observe: (a) Björndalen's ankle is flexed forward a little more than mine at the instant his foot lands, and I think also flexed forward more at the end of the leg-push. (b) Björndalen plants his poling-side a little before he lands his poling-side leg, and his poling-side hand starts alongside his ear. I plant my poling-side pole simultaneous with landing my poling-side leg, and my hand starts in front of my head, so my pole starts more angled back and his starts more vertical. (c) B is extending his leg out to a bit closer to straight than mine in my V1 side-view video. Though in my V1 front-view video I'd guess I'm extending out as far as him. (d) In the pole-push, B is driving his hands down lower than mine, and then further back than mine. I think my poling motion gets closer to B in my V1 front-view video. A hypothesis is that in the side-view video, the steepness and slow snow were too much for my non-elite muscles to handle with V1, and I should have switched to single-poling "coaches" skate. Comparing my V1 front-view video with the other racers (since there's no front-view of Bjorndalen): (e) While pushing on my recovery side I'm bending my torso sideways so that my recovery-side shoulder is more over my recovery-side foot -- that's a deliberate attempt to maximize my side-to-side weight shift. (f) But sometimes I also see what looks like some bending of my torso backward which Andrew mentions -- which is not deliberate and for which I cannot imagine a positive benefit. (I'm thinking instead that when I swing my shoulders over to the recovery-side, I need to keep them lower longer, and focus more on moving fully sideways first, rather than get diverted into rising upward too early.) (g) The elite racer's heads are much more stable than mine in the V1 front-view video. Though I think my head-stability in the other videos (notably the Legs-only front view) is better. My response to those observations is that I'd like to make all of those difference points to become less different -- except maybe (e). What do you see as different? I see some timeshift between the upper and lower body movment. I do think that O-E have longer poles compared to you. He does a more compleate weighttransfer on every cycle and gets more glide out of it. He does a lower more economical lift when doing the recovery and also he does not "stamp" down the skii after every recovery, he "glidestart" every stroke. Further down i the clip we have some frontviewshot. Comparing yours with that i notice that you only glide on your left leg and don't do anything with your right leg, it looks like it's just hanging there straight after setting down the skii on the surface. You are workig wery hard on your left leg but not on the right and therefore the strokecycle seams a little odd. Look how much all are working with both legs when climbing, just because we emphasis one side by "hanging" or going forward with the poles on that side doesn't mean that the oposite side is going to just hang there doing nothing (ok, doing 30% while the other side doing 70%). And yes i know that it isn't fair to compare some like O-E Björndalen in an unknown climb with people like us. But i can't se any other way. Don't take this as a guide for what to do, this is just my reflections on the videos. Janne G |
#13
|
|||
|
|||
Janne G wrote
O-E Björndalen does a lower more economical lift when doing the recovery and also he does not "stamp" down the skii after every recovery, he "glidestart" every stroke. I agree with that observation -- and it leads to a whole new idea about technique for me. The reason I intend to lift the ski higher is in order to "stamp" it down, and the reason I intend to stamp it down is to guarantee that one of my legs is always pushing -- to ensure that there is zero passive-glide "dead time" for my legs. So I start my next leg-push even before I have finished the previous one, and I think my next leg is thus already generating some reactive-force propulsive work even before it hits the snow. I think the disadvantage is that this stamp or stomp increases the sliding friction of the ski, especially in softer snow. But looking at Björndalen's "glidestart", I'm wondering if he's not actually pushing simultaneously with _both_ skis for one or two video frames, less than 0.1 second. It looks to me like his heel stays down on the ski until after the other ski lands. So if his heel coming up off the ski indicates that he is applying propulsive force thru the ball / toe of his foot, then he is transmitting force to the snow thru both skis simultaneously. I think in that striking close-up of footwork in the skateFeetSlomo.mpg Techic video - (Thanks for much for recognizing the importance of that and putting it up on the Web for us, Janne) - viewing with single-frame-advance during time :13 second, I see about 3 or 4 frames of overlap between the two leg-pushes. So if the slow-motion is at half-speed, that's around 0.06 second of overlap. The advantage of this overlapped timing of leg-strokes in the physics is that you can get a larger range-of-motion with the same turnover frequency, or the same leg-push range-of-motion with a faster turnover frequency -- and either one implies a higher output rate of propulsive power. I had noticed this kind of overlap before in the V2 of elite racers, but I hadn't been ready to see that it might be happening in V1. I wanna try for it. Ken _______________________________________ Janne G wrote I see some timeshift between the upper and lower body movment. I do think that O-E have longer poles compared to you. He does a more compleate weighttransfer on every cycle and gets more glide out of it. He does a lower more economical lift when doing the recovery and also he does not "stamp" down the skii after every recovery, he "glidestart" every stroke. Further down i the clip we have some frontviewshot. Comparing yours with that i notice that you only glide on your left leg and don't do anything with your right leg, it looks like it's just hanging there straight after setting down the skii on the surface. You are workig wery hard on your left leg but not on the right and therefore the strokecycle seams a little odd. Look how much all are working with both legs when climbing, just because we emphasis one side by "hanging" or going forward with the poles on that side doesn't mean that the oposite side is going to just hang there doing nothing (ok, doing 30% while the other side doing 70%). And yes i know that it isn't fair to compare some like O-E Björndalen in an unknown climb with people like us. But i can't se any other way. Don't take this as a guide for what to do, this is just my reflections on the videos. Janne G _____________________________________________ |
#14
|
|||
|
|||
O-E Björndalen does a more complete weight
transfer on every cycle and gets more glide out of it. Without doubt he gets more glide than me. My obvious interpretation is that's because Björndalen is twice as fast as me, using about the same turnover frequency, therefore he's going twice as far in every leg-stroke. If I cut down my turnover frequency, I might glide a little farther in each stroke, but I'm guessing that my muscles would be more burned out when I got to the top of the hill. Weight transfer -- what is it? Seems very clear to me in Classic striding: Complete weight transfer is when I take all my weight off one ski (and better yet take it off both my poles too) and put it all on the other ski. So if I watch a video of Classic striding and see one ski completely off the snow and both poles off the snow, then I can infer that "weight transfer" is 100%, and that's the maximum. If I see the other ski on the snow and out toward the back only the toe touching down, and the heel off the snow, I might guess that it's 75%. But if the other ski were on the snow directly underneath the skier's hips, I'd say the weight transfer is only 50-60%. But in skating, what is "weight transfer" really? (and how measure it off a video?) I think it's clear in all four of my videos that most of the time only one of my skis is on the snow and the other one is up in the air somewhere, so by the Classic-striding definition I have achieved 100% complete weight-transfer (between my legs). So when somebody says I have "less weight transfer", it can't mean that. Perhaps it means the amount of time I spend with all my weight on each single leg before I land the other one. Basically that's just 60 seconds divided by my 2 times my stroke-cycle turnover frequency per minute. Which is just another way of saying my turnover frequency is higher than it could be. Actually I've measured my turnover frequency and it's not much different from the elite racers climbing up hills. Anyway if "time until you put the other leg down" is what we really mean, then why not just keep it simple and measurable and talk about "turnover frequency". So I guess it must mean something else, like how far you get out over one ski. Or maybe how far you get out toward one side (aside from where the ski went). Which raises the messy but critical detail of what the "you" is -- your hips? your navel? your true center of mass which is fully dynamic and not linked to any body part? Then there's the other question of what the "get out over" means -- rotate to face toward the ski (as in Nose-Knees-Toes), or shift (a.k.a. "translate") position sideways, or tilt sideways -- or some combination of those? Finally once you go to the trouble of selecting and carefully describing some set of those options as the "definition" of weight transfer for skating, then how will you convince anybody else that it's better than seventeen other similar-sounding definitions? Anyway, I agree that some sort of weight transfer in skating is a good thing, and that Björndalen probably has more of "it" than I do in in my V1 Side-view video -- and I wish I had as much as him. Maybe I was not focused enough on weight transfer there on that hill? Or don't know what it is I'm supposed to be focusing on? Or was that hill just too steep for me in fresh cold snow? But it does seem to me that a Front-view video offers a more accurate way to analyze weight transfer, and I feel like I see a lot of weight transfer in my V1 Front-view, and even more in my Legs-only Front-view. Like if I pause the Legs-only video at the moment my pushing ski finishes, it's not easy for to imagine how my pushing hip could be moving any further toward the other side than it is -- because my leg is leaning at a 40-45 degree angle from vertical, and very straight with the toe pointed. And it's difficult for me to imagine how I could have committed my torso-shoulders-head any farther over to the other side -- whether you want to define it as rotate or shift or tilt doesn't matter -- because I'm doing all three at once. Then as I continue thru the first phase of the next leg-push, my head moves to directly over my ski boot, so one shoulder and arm are out there sideways further than my pushing foot. I guess I if we want to define "weight transfer" as relative to the next pushing ski, I could have gotten more if I had simply landed the ski down more underneath me. I think what I see is that in my leg-recovery move I bring my ski in to nearly underneath my next pushing hip, but then I send it out again, and end up landing the ski distinctly outside the pushing hip. Perhaps if we had a straight Front-view of Björndalen, we'd see him landing his ski directly under his pushing hip, or less far out then me anyway. Is that what ought to be meant by "more complete transfer" ? or what? Seems like an important question, if we're want to use video to improve skating technique. Ken __________________________________ Janne G wrote I see some timeshift between the upper and lower body movment. I do think that O-E have longer poles compared to you. He does a more compleate weighttransfer on every cycle and gets more glide out of it. He does a lower more economical lift when doing the recovery and also he does not "stamp" down the skii after every recovery, he "glidestart" every stroke. Further down i the clip we have some frontviewshot. Comparing yours with that i notice that you only glide on your left leg and don't do anything with your right leg, it looks like it's just hanging there straight after setting down the skii on the surface. You are workig wery hard on your left leg but not on the right and therefore the strokecycle seams a little odd. Look how much all are working with both legs when climbing, just because we emphasis one side by "hanging" or going forward with the poles on that side doesn't mean that the oposite side is going to just hang there doing nothing (ok, doing 30% while the other side doing 70%). And yes i know that it isn't fair to compare some like O-E Björndalen in an unknown climb with people like us. But i can't se any other way. Don't take this as a guide for what to do, this is just my reflections on the videos. Janne G __________________________________ |
#15
|
|||
|
|||
Jim Grau wrote
I can see one difference between Ken and the elite skiers in Janne's collection: I see more forward hip rotation in the elite skiers Hip rotation. Forward. Wow! Somehow I never noticed that before in the elite skaters. First let's make sure we're clear on which kind of rotation we mean. What I'm seeing is that at the start of the leg-push, the non-pushing-side hip starts behind the other hip, but it finishes ahead of the pushing hip. So the hips have rotated so that the skier's pelvis starts "facing" a bit away from the current leg-push side, and finishes facing a bit toward the leg-push side. Physics -- I can see how this hip move helps in climbing up a hill, because it uses some sort of "pelvic rotator" muscles to move the non-pushing leg say like 5 cm further forward, which on a hill of 10% steepness grade yields a 0.5 cm advance in the fight against gravity for the mass of one leg -- which is a substantial percentage of the skier's whole body. There's a bit of inefficiency with the transmission of the reactive force from this work into the snow thru the skier's already-pushing leg. So overall there's a net increase in uphill propulsive work without changing turnover frequency, and therefore an increase in total power and thus the skier's speed up the hill. Or the skier could choose to go easier with his main leg-push and poling muscles, and allow this new "pelvic rotator muscle" work to maintain the same total power rate as before -- but with less lactate load on the main pushing muscles -- and just get to the top with more energy leftover to enjoy the rest of the day's skiing. I like that picture. I'm not worried about putting load on my "pelvic rotator" muscles, because they don't have much else to do anyway. Except I better be careful not to overdo it in the first week or month or so -- I don't want to miss four days of skiing recovering from a strange new muscle strain. I'm seeing the elite racers also rotate and/or shift and/or tilt their shoulders in the opposite direction from their hips -- away from the currently pushing leg. But not as much as I do. Finally I see the good reason to limit my shoulder swing -- in order to get more out of my hip rotation. A few months ago I said on this newsgroup that I used the concept of rotating my non-pushing hip forward -- but not for propulsion, and not to actually move it forward -- only to make sure that it did not rotate backward. The elite racers had a better idea. I can't wait to try it. more . . . * My analysis of the physics is on flat terrain that forward hip rotation has much less net forward-propulsion benefit -- except in softer slower snow (? or maybe into a headwind ?). * Classic diagonal stride -- eliter racers use "forward" hip rotation to increase forward propulsion power. Again by advancing the non-pushing hip. And they also counter-rotate their shoulders -- so the shoulder opposite to the soon-to-be-pushing leg moves backward -- I think to help with the "diagonal" pole push. (Interesting that the way the Ultimate Master does weight transfer in Classic striding: Elena Vaelbe minimizes side-to-side motion of her hips, and mostly moves her shoulders across to the side of her next pushing ski -- see the great rear view in the Norwegian Ski Federation instructional videos from Trondheim 1997.) * backcountry striding -- Sharon started playing with hip rotation to help climb up very steep hills with climbing skins on her skis. Then I found out that two of the fastest non-racer mountain touring skiers I know make big obvious use of forward hip rotation to help them climb big hills. Ken ____________________________________ Jim Grau wrote Ken, I think what you're doing here can spark some really helpful discussion. Most of us who are still struggling to improve our technique no doubt look a lot more like Ken Roberts than Carl Swenson, so your videos may make it easier for us to see what needs to be changed. Bearing in mind that I'm just a struggling skier who gets blown away by Ken on the uphills, I can see one difference between Ken and the elite skiers in Janne's collection: I see more forward hip rotation in the elite skiers vs a deeper knee bend from Ken. Whether we should be consciously thinking about it or not, it seems we DO need to bring the foot forward and upward to get up the hill, and what I see in Ken's video (and probably in mine if I had one) is that he's moving the foot upward and forward by bending the knee with a fairly stationary hip, which tends to put the hip back; whereas the elite skiers move the hip forward and upward with consequently less knee bend. I never did totally understand the concept of "keeping the hips forward", but somebody (maybe Ken actually) pointed out something that might be important: that "hips forward" should not be thought of as a "position" but rather as a "move", as in your hips shouldn't be forward all the time, but rather moved forward at the right time. It seems to me that the elite skiers are doing this by rotating their hips, both in V1 skating and in classic. I suspect there's some disagreement about hip rotation since I distinctly recall an article in the Master Skier suggesting skating no poles with your poles behind your back so that any of this presumably undesirable hip rotation would be accentuated. Hopefully some of the technique experts can weigh in and set me straight here. Again, I applaud Ken's courage for posting the videos and I hope they solicit more discussion that we strugglers can find helpful. Jim ____________________________________ |
#16
|
|||
|
|||
Well Ken, the technique looks better than last year. I quickly skimmed
over the replies and looked at the side view video. Now, I'm not a coach and I don't play one on TV, but two things strike me. One is that your upper body seems to be flailing. Maybe you were really hammering for the camera, but the coordination didn't seem to be there (which comes with years of skiing) and there was lots of movement. As you ski more and get a stronger upper body, it seems the upper body doesn't feel like it moves a lot but the muscles (abs, chest, lats) are really contracting. Remember that if you bend over to push, you have to bend back, and the bending back is mostly wasted energy. The other thing was the stomping. Usually I associate that (with myself) when I'm off-balance or skiing through 6" of sugar or climbing a super steep hill. There's no need to pick the ski up more than just enough to clear the snow (watch Isometsa, who seemed to splash some snow about every 5th stroke). Also, power in skiing seems to be associated with being smooth with the legs. You can suddenly apply power to the arms, but the legs usually work in a nice smooth pendulum motion. Maybe think of a speed skater doing a long distance event. Jay Wenner |
#17
|
|||
|
|||
Andrew Lee wrote
Swing (not lift) your leg forward with your abs... You can figure out how to do that now in the house. Visualize your legs going all the way to the bottom of your ribs and move from there. OK I'll try that. Andrew is right that I can feel the difference in my living room. Actually I'm not sure why thinking about moving my leg should help much. But that's OK -- I'm happy to try new moves and figure out the physics/biomechanics later. (Is this move at all related to what Jim Grau said about "forward hip rotation"?) Your weight is on your heels. You are skating like a speed skater pre-clap skate. It was very noticeable to me that your boots never come off your skis. I agree with this observation that my heel stays down thru virtually my whole leg-push, though I think my heel usually does come up just as I'm finishing my leg-push. But I'm not seeing where to go with this, because it looks to me like the same observation about "heels down thru almost the whole leg-push" can be made about Bjorndalen and all the other elite racers in Janne G's video -- and to me it looks even more clear in that footwork close-up video on Janne G's Technic page: skateFeetSlomo.mpg ... you having fore-aft balance problems (where you seem to get your upper body too far forward . . . I agree with the observation that my upper body is leaning way forward. But it looks to me like most of the elite racers in JanneG's videos are leaning way forward also -- and it seems roughly as far as me, but sometimes more. I know skating is complicated -- so I'm glad to say I'm missing some key aspect -- what is it? If you keep your torso connected with your pelvis with body tension, ALL of your upper body will be involved with weight shift (not just your torso) I think I'm hearing that maybe my pelvis and hips are not properly shifting sideways. To me that sounds undesirable, since I really believe in side-weight-shift, and I really believe that it's more important for my hips, than it is for my torso and shoulders. I really believe that the shift of my shoulders is only a supplement to be added after strong hip+pelvis side-weight-transfer is achieved. I'll give up some shoulder-torso-swing if I really understand how that's going to increase my hip+pelvis action, but not if I haven't heard how at least a good hint at how proper hip weight-transfer should be defined and observed -- so I could know when I'd finally "got" it. So like in my Legs-only Front-view video, or my V1 Front-view, what is the observation that shows that my hips or pelvis (or something) is not getting enough weight-transfer? In what phase of my leg-push: set-down? final extension? you are even arching your back backwards the V1 front view video ... your upper body should move as a whole. I agree with that observation about arching back, and that I don't like it and want to get rid of it. And I agree with the observation about the elite racers (this time) in their torso-side-moves do not curve their torso sideways like I do -- so thanks for exposing me to that. But this is one case where I'm not yet ready to copy the elite racers -- in the side-curve-bend of my torso. I don't buy the "upper body should move as a whole" because to me it's like what the US National team coaches have been pointing out for years about the benefit of forward-curvature of the torso -- that in the pole-push it's important to curve the shoulders-chest-abdomen (the C position), and have warned against the mistake of hinge at the waist and keep the torso straight in poling. I agree with those National coaches, and in the last six months on the newsgroup gave a difficult-to-understand justification of the physics and biomechanics of why the curved C position is better. I'd be glad to hear some arguments for why side-curvature is bad even though front-curvature is good, or for why its side-effects are inevitably bad. But for me it's got to be something more than just "quieter is better". Because climbing up a hill is an act against nature. Ken __________________________________ Andrew Lee wrote Ken, at times I almost think that you are trolling ;^) I also taught myself and I shudder to think how I looked skating my first two years, but I think that my learning process made me very aware of what mental technique pointers worked for me. I also have skating imprinted into my brain from watching and rewatching the 1998 Olympic tapes continuously one winter (and later 2002 Olympics and Janne's technique videos) during the time I finally picked up how to skate correctly. Here are the things that I noticed on your new videos: Your weight is on your heels. You are skating like a speed skater pre-clap skate. It was very noticeable to me that your boots never come off your skis you could probably ski the same way if your heel was fixed! You should be aware of your center of gravity. When your weight is back, your COG is over your heels and that's where you feel the pressure in your feet. You need to shift your weight forward so that your COG is over the front part of your foot... the ball of your foot or just behind the ball of your foot. If you feel the most pressure at that point when you skate off, you know you have it right. References from memory: Galanes (RSN poster "Jim") wrote that the push should be with whole foot, with greatest pressure on the forefoot. Abby Larson had an article a while back somewhere where she says that she can tell she is in the right fore-aft position when her weight is on the front part of he feet. You are not using your abdominals, at least not to the extent that you should or the way that you should. One part of it is the running thing that Gene mentioned in your forward step. Getting this right was THE key for me (I picked up the tip from the archives of RSN a couple of years ago). Don't step forward with your leg. Swing (not lift) your leg forward with your abs... You can figure out how to do that now in the house. Visualize your legs going all the way to the bottom of your ribs and move from there. During my first two years of skiing, I never used my abs. One time, as I was skiing behind my friend up a long hill, I asked her if she was using her abs and she told me OF COURSE! and that it was almost cramping up. She's a high level skier, so that was a wakeup for me. Anyway, that visualization for bring the leg forward turned my skiing around within minutes of trying it. Immediately my upper body was more stable. In the legs only views, you can tell that you are not using your abs and that it is resulting in you having fore-aft balance problems (where you seem to get your upper body too far forward and need to correct...). I agree with Gene on your upper body. You should shift your weight around and compress to some extent, but your upper body should move as a whole. Dang, Ken, you are even arching your back backwards the V1 front view video (the side view doesn't look as bad). If you keep your torso connected with your pelvis with body tension, ALL of your upper body will be involved with weight shift (not just your torso) and the overall movement will be quieter. It's an easier and more effective way of loading your weight on your kicking (skating) foot than what you are doing with the extra torso movement. Keep your head steady too. _____________________________________ |
#18
|
|||
|
|||
Ken Roberts wrote: Andrew Lee wrote Swing (not lift) your leg forward with your abs... You can figure out how to do that now in the house. Visualize your legs going all the way to the bottom of your ribs and move from there. OK I'll try that. Andrew is right that I can feel the difference in my living room. Actually I'm not sure why thinking about moving my leg should help much. But that's OK -- I'm happy to try new moves and figure out the physics/biomechanics later. (Is this move at all related to what Jim Grau said about "forward hip rotation"?) Yes, it is related to what Jim said. It will stabilize you more than you can believe if you haven't tried it yet on snow. You might be able to see it in the videos if you know what to look for - it's a elastic springiness to their hip/ab movement that shows that they are using those muscles. I notice it even in the leg skating videos. The stability will help you reduce extraneous upper body movement. Your weight center will no longer be all over the place, so you will be able to smoothly shift it much easier. I use this for all the skating techniques and classic as well. Your weight is on your heels. You are skating like a speed skater pre-clap skate. It was very noticeable to me that your boots never come off your skis. I agree with this observation that my heel stays down thru virtually my whole leg-push, though I think my heel usually does come up just as I'm finishing my leg-push. But I'm not seeing where to go with this, because it looks to me like the same observation about "heels down thru almost the whole leg-push" can be made about Bjorndalen and all the other elite racers in Janne G's video -- and to me it looks even more clear in that footwork close-up video on Janne G's Technic page: skateFeetSlomo.mpg I could tell without detailed observation that you were skating off your heels - it just looked like that in my first impression on the side views. It might be a factor in limiting your leg extension. If you try it both ways dryland, you might notice the difference. This is pretty much an easy fix I think. Just keep your weight centered over the front of your feet and feel the pressure just behind the ball of your feet when you push off and rest will probably take care of itself. ... you having fore-aft balance problems (where you seem to get your upper body too far forward . . . I agree with the observation that my upper body is leaning way forward. But it looks to me like most of the elite racers in JanneG's videos are leaning way forward also -- and it seems roughly as far as me, but sometimes more. I know skating is complicated -- so I'm glad to say I'm missing some key aspect -- what is it? I was noticing the bobble and instability, not the angle so much. See my first point. If you keep your torso connected with your pelvis with body tension, ALL of your upper body will be involved with weight shift (not just your torso) I think I'm hearing that maybe my pelvis and hips are not properly shifting sideways. To me that sounds undesirable, since I really believe in side-weight-shift, and I really believe that it's more important for my hips, than it is for my torso and shoulders. I really believe that the shift of my shoulders is only a supplement to be added after strong hip+pelvis side-weight-transfer is achieved. I'll give up some shoulder-torso-swing if I really understand how that's going to increase my hip+pelvis action, but not if I haven't heard how at least a good hint at how proper hip weight-transfer should be defined and observed -- so I could know when I'd finally "got" it. You can keep the swing, but more pendulum like without the flailing. So like in my Legs-only Front-view video, or my V1 Front-view, what is the observation that shows that my hips or pelvis (or something) is not getting enough weight-transfer? In what phase of my leg-push: set-down? final extension? It looks like you are getting good weight transfer - you are moving up the hill pretty well. you are even arching your back backwards the V1 front view video ... your upper body should move as a whole. I agree with that observation about arching back, and that I don't like it and want to get rid of it. And I agree with the observation about the elite racers (this time) in their torso-side-moves do not curve their torso sideways like I do -- so thanks for exposing me to that. But this is one case where I'm not yet ready to copy the elite racers -- in the side-curve-bend of my torso. I don't buy the "upper body should move as a whole" because to me it's like what the US National team coaches have been pointing out for years about the benefit of forward-curvature of the torso -- that in the pole-push it's important to curve the shoulders-chest-abdomen (the C position), and have warned against the mistake of hinge at the waist and keep the torso straight in poling. I agree with those National coaches, and in the last six months on the newsgroup gave a difficult-to-understand justification of the physics and biomechanics of why the curved C position is better. I guess my point wasn't clear. I'm not saying anything about whether there should be a curve or not, and I'm not saying to bend at the waist. The curve is a good thing. The lower part of the C is maintained by the muscles that I was referring to in my first point (psoas?). I was thinking of two things: the back arching and instability. I'd be glad to hear some arguments for why side-curvature is bad even though front-curvature is good, or for why its side-effects are inevitably bad. But for me it's got to be something more than just "quieter is better". Because climbing up a hill is an act against nature. No one else does it, right? Maybe it isn't inevitably bad. Some top marathoners do some weird form things (Paula Radcliffe's head bobble, some top Chinese runner's straight arms, etc.). But it looks like flailing to me. If you can get on some snow (in Europe?), try the ab driven leg recovery and the weight over the front of the foot things. |
#19
|
|||
|
|||
Andrew Lee wrote
... try the ab driven leg recovery ... Yes I did, and I like it. I haven't actually done any sort of side-by-side comparison against my old way, because once I got into doing Andrew's new thing I found I had no interest in going back. I started by just trying Jim Grau's idea of "forward hip rotation". One nice thing about hip rotation is that you can observe it without video -- just look down. What I soon observed was that I wasn't actually doing it what I thought I was trying to do. Then I realized I'd better use Andrew's image of thinking of my leg as attached to the bottom of my rib cage. And that worked. (except that sometimes I skied into the edge of the trail because I was looking down at my hips to check). I'm thinking it's like Andrew's image is the "subjective" approach and Jim's concept is the "objective" approach -- and some people need one and others need the other, and a few of us "resistant" types need both. ... try the weight over the front of the foot ... Yes, this tip worked well for me too -- especially in the final phase of my leg-push, when I combined it with JanneG's and Jay "Bjorne" Wenner's idea of setting the next ski down low and smooth. I liked what happened when I would land the next ski early, before the end of previous leg-push -- then focus the finish of that old push on the fore-foot. Felt like that helped me direct that final push into the line of the new ski -- which when I was climbing up a steep hill was aimed distinctly out to the side. I would also "slice" the pushing ski forward in that last phase of the push. So it was not like a runner's toe-push aimed toward the back. Instead it felt like it was pushing me over to other side (? more weight transfer ?), and thus enhancing the glide of my next ski out to the side. This is great, because for keeping my ski gliding up a steep hill in soft snow, it needs all the help it can get. During the early or main phases of my leg-push, I found it hard to make myself focus on my forefoot. Out of the few times I could talk myself into it earlier in my push, at least once it seemed to bog my ski down and almost stop my glide -- because I was in soft snow. Maybe I need an additional tip about that. Overall I spent about three hours skiing with no poles -- made it thru all the black trails ("most difficult") -- the later 2 hours was in mushy snow, the last hour to the point of "ugly". Never thought I could do that before. But even in the midst of the most heinous climbs, I never thought about going back to my old ways. So thanks a lot to Andrew Lee and Jim Grau for taking me to something new. Ken |
#20
|
|||
|
|||
Jay Wenner wrote
stomping . . . You can suddenly apply power to the arms, but the legs usually work in a nice smooth pendulum motion. I figure when both JanneG and Jay are telling me the same thing, I ought to do something about it. So I started playing with recovering the ski low -- it was firm snow in the first half hour, so I actually dragged the non-pushing ski on the surface. No problem for me -- good positive start. (This and what follows was with no poles -- didn't use poles the whole day) Then I tried what I was seeing in JanneG's Technic video skateFeetSlomo.mpg -- of landing the next ski before I finish the previous push. This was hard for me at first. I really had to force myself -- seemed sorta like I had to pause my leg-push for an instant, consciously set the other ski down, then finish the leg-push. (I assume it would get smoother with more practice). I tried for, but did not achieve my idea of pushing on both skis simultaneously. This early smooth landing definitely eliminated my "stomp" move, and I really liked the feeling of the smoothness (regardless of what plus or minus in physical effectiveness might result). Somehow it also seemed to help me focus more on getting the most out of the final phase of my leg-push, and to direct that push toward the other side, and into helping my next ski glide out to the side more (? better weight transfer ?). For me that side-glide is really critical for surviving skating up hills slowly, without burning out. So I started testing this new capability in skating up tough hills on the "most difficult" black trails (with no poles). By now the snow had turned mushy, and later got to the point of ugly and nasty. And the low recovery and smooth set-down kept on working for me. Not an enormous surprise, since soft snow is exactly where "stomp" has its worst effect. I tried going beyond that. I decided to deliberately set the new ski down on top of the tail of the old ski. So I could hear the "click" -- the base of one ski landing on the top of the other. While climbing up a substantial hill. And it kept working for me. As the next ski landed, I would aim it further out toward the side (not up the hill), and aim my knee along with it. Then I'd consciously do the final push off the old ski thru the forefoot, like Andrew Lee suggested. Somehow all that fit together nicely for me. I don't understand all the biomechanics and physics of why smooth and low and early landing is better than "stomp" (or if it actually is in all situations). All I know is I kept on doing it for 2 hours in the toughest hill-climbing situation I can remember, and it kept working for me. So much thanks to JanneG and Jay Wenner. Ken _________________________ Bjorn A. Payne Diaz wrote Well Ken, the technique looks better than last year. I quickly skimmed over the replies and looked at the side view video. Now, I'm not a coach and I don't play one on TV, but two things strike me. One is that your upper body seems to be flailing. Maybe you were really hammering for the camera, but the coordination didn't seem to be there (which comes with years of skiing) and there was lots of movement. As you ski more and get a stronger upper body, it seems the upper body doesn't feel like it moves a lot but the muscles (abs, chest, lats) are really contracting. Remember that if you bend over to push, you have to bend back, and the bending back is mostly wasted energy. The other thing was the stomping. Usually I associate that (with myself) when I'm off-balance or skiing through 6" of sugar or climbing a super steep hill. There's no need to pick the ski up more than just enough to clear the snow (watch Isometsa, who seemed to splash some snow about every 5th stroke). Also, power in skiing seems to be associated with being smooth with the legs. You can suddenly apply power to the arms, but the legs usually work in a nice smooth pendulum motion. Maybe think of a speed skater doing a long distance event. Jay Wenner |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
This can make you some extra cash, check it out. | Nick Burns | Snowboarding | 0 | July 14th 03 04:32 PM |
This can make you some extra cash, check it out. | Nick Burns | North American Ski Resorts | 0 | July 14th 03 04:32 PM |