Sashas Edges

Centripetal. ("Centrifugal" force isn't really a force, it's a consequence of Newton's first law.)

It must be an equally awesome sight to behold, (if there is a way to get there) when a star is born.

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Maybe we can't get there, but the Hubble and Chandra telescopes can. I did a search on "star born" and found these pictures:

http://www.abc.net.au/science/news/space/SpaceRepublish_249630.htm
http://www.abc.net.au/science/news/space/SpaceRepublish_910345.htm
http://home.swipnet.se/~w-18501/Bilder/Star/star02.jpg

MM

Rgirl said:

RG#1--Ta-MOOOOOO!
Mzheng--Love and appreciate your biomechanical analyses, but I disagree with your assertion that doing a FIE spiral should not make it any more difficult to get a deep edge. True, the COG is the same but not the relationship of the weight of the extremities, specifically the free leg (FL) relative to the FIE. When doing a FOE spiral, the FL is on the opposite side of the edge lean. But when doing a FIE spiral, the FL is on the same side of the edge lean, this putting more weight on the same side toward which the skater is leaning toward. No matter high high the FL, this makes it more difficult to get as deep an edge on the FIE spiral than on the FOE. That's why skaters who get great depth of edge on both their FOE and FIE spiral would certainly get maximum points for that move from Judge Rgirl. I think if you try it even in barefeet and not moving you'll feel the difference.

Rgirl

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Rgirl, you misunderstood what I said in my posts.

In my very first post, where the intunative formular given, I said exactly what you said but not as clearly. That it is easier for a skater to get a decent FOE than FIE in spiral position. In general, the FIE spiral need more speed -- since there is more centerforce need to be balanced out -- assuming the same edge (@) is achieved.

In my last post to answer someone 'if you are in a 180 split it is harder to get deep inside edge compared to not a 180 split'. My thought is that
1) Assuming the FL is in the back of body position, then the higher or lower FL dosen't affact the center of the body left or right, only front or back position, the higher the FL the center of the body move toward forward, which dose not exert extra center force. In that sense I'd say 180 split or less 180 split (here we say someone can hit 180 easily on FOE spiral) should not affect the difficulty of achieving deep inside edge.
2) Assuming the FL is a little turn out on the side, then I would say less 180 split will move the center of boy toward spiral center, which exerts extra center force, which inturn need more speedy to balance out the center force.

All in all my point is that the speed is the key factor affect skater to achieving deep inside edge. Not the 180 split.


rtureck,
I think a more persice equation would be as following -- I posted a while ago on MKF -- though I don't have the time get is resolved.

I think the key is the V shape the blades cut in the ice. And the ice supporting force applied to the flat and one side (either inside or out side depends on which foot on the ice) of the blades. The 2 forces one perpendicular to the the left side \ of V (call it Fleft) and the orther perpendiculer to the right sied / of V (calle it Fright).

Assuming skaters lean to right at angle @ against the ice surface. Then the \ side provides the support force to the flat of the blads. Which also become contributor to the C force. Thus we have

To balance Gravity:
Fleft * Sin@ + Fright * Cos@ = Gravity.

To balance Center Force:
Fleft * Cos@ - Fright * Sin@ = mv^2/r

The leaner, the smaller @, the biger Cos@ and the smaller Sin@ if you maintain the same speed (v) and same curve (r) then you would fall towards the center. To avoid the fall you need either increase your speed(v) or increase the curve degree (reduce the r).

In another word if you don't have enough speed and good degree curve you can't lean too much of your body to the center of the circle or you'll lose your balance. Thus in judge's eye your edge is not that deep. Judge weren't use this formular they just observe the body positions.

So all in all is the skaters have to search for the balance point of the body lean(@), speed(v) and curve degree(r) on ice. It IS difficult.

Spirals, spirals and more spirals. Real men don't do spirals.

It's funny some people don't think it is a difficult move and yet it is.

I am certain that the most difficulty in executing a spiral is the solid edge, and it becomes more difficult when there is a change of edge. (My old friend Tara did hers on the flat - ez!).

For me, and I think, in general, the back inside edge is the most difficult edge in figure skating. I believe I saw Irina do a bo spiral into a bi spiral. It was not done well, but I gave her extra points for attempting that - not ez!

Any way, look for solid edges and holding those edges for a period of time. That's what it's all about.

Joe

John Curry did spirals--they were beautiful.

Oddly enough I've always found spirals to be most difficult ON a flat. And I began doing them on an inside edge, so I used to think the outside edge was uber hard.

Mzheng,
My humble apologies. I did misread your post. Reading this one, I completely agree with everything you say. You know your Newtonian mechanics backwards and forwards, inside and outside And you're so right about speed Having done spirals (not well) 20 years ago, speed is the key to getting a deep edge, especially FIE.

Joe,
In addition to John Curry, who was mentioned, Paul Wylie had one of the most gorgous spirals I've ever seen when he was skating at his peak. Great speed, great edges, and oh, what a beautiful line.
Rgirl

Hey, Idle, how come you changed the hockey guy into Michelle Kwan???

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And an astonishingly beautiful MK spiral at that. I just downloaded it for my gallery, LOL.

Speed is the key to getting a deep edge. -- Rgirl

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v*v/r = G cos*@...Since v is proportional to cos * @, that means, the more the lean, (smaller @) the more speed v the skater has to generate to maintain that small angle. -- RTureck

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In fact, if you look closer, it is v squared that is proportional to cos@. For angles near 45 degrees, the change in cos@ is in turn proportional to the change in @ itself. (This relation changes for angles closer to 0 or to 90 degrees.) So the change in edge angle needed to maintain balance is proportional to v * (change in v). That would help to explain why it is harder to make those little changes in edge angle when you are going fast already.

About the 180 degree split, if you also have a good arch in your back, with your head up (the better to smile at the judges, while simultaneously treating the photographers behind you), it seems to me that this shortens your base and makes it more difficult to keep your skates under your center of gravity back to front -- think of a pencil skating on its point.

Mathman said:

So the change in edge angle needed to maintain balance is proportional to v * (change in v). That would help to explain why it is harder to make those little changes in edge angle when you are going fast already.

About the 180 degree split, if you also have a good arch in your back, with your head up (the better to smile at the judges, while simultaneously treating the photographers behind you), it seems to me that this shortens your base and makes it more difficult to keep your skates under your center of gravity back to front -- think of a pencil skating on its point.

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Yeah, Mathman, ITA with your first explaination of v and @ relationship through differentiation.

I also agree that 180 degree split -- as you pointed out the moving the center of gravity to front -- makes it more difficult for keeping the skates under the center of gravity. But my point was if a skater, like Sasha, could get decent edge in her FOE with a 180 split -- which also move her center gravity to front -- theoritically, the 180 split should not affect her edge on FIE, the only factor leaves the speed. Skater need more speed to balance out the extra center force which drawn from the center of gravity moving towards the spiral center.

mzheng:
The leaner, the smaller @, the biger Cos@ and the smaller Sin@ if you maintain the same speed (v) and same curve (r) then you would fall towards the center. To avoid the fall you need either increase your speed(v) or increase the curve degree (reduce the r).

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OK, since I have the most difficulty with the r from this equation, what is r, is it the radius from the center point of the centripetal force to the skater's blade, i.e. edge that forms the @ on the ice?

Mathman:

About the 180 degree split..... seems to me that this shortens your base and makes it more difficult to keep your skates under your center of gravity back to front -- think of a pencil skating on its point.

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What do you mean by shortening the base

I can see that multi factors contribute to the technical difficulties of a spiral. So one has to integrate all these factors to determine who are the skaters with the overall best. I think actually Sarah Hughes our reigning champ has one of the overall best in the world. I know, a lot of people find fault because her knee is a bit bent, that is her anatomy, she can't do much about it. But if you look at her powerful deep forward inside edge, the speed , the ice coverage and the amplitude. I think she has an amazing spiral.

IMHO NO ONE manages a complete 180 degree split, and Sarah's split is very close to 180 degrees.

Mathman:
..... with your head up (the better to smile at the judges, while simultaneously treating the photographers behind you)

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This is the non technical part of the spiral, I guess the smile is important, that is why I think Nicole's spiral is the mother of all spirals. Her smile lights up the entire arena. Some skaters like Sarah really draws the audience into her performance with the spiral Although 4DKnight pointed out in another thread that Sarah's hands and fingers are not exactly the most expressive, "thumbs hanging down"

Oh well no one is perfect, but Sarah comes very close. Talking about the fingers, I have to agree with Joesitz that Yukina Ota is tops. If you have time watch her Turandot program from junior worlds 03 again.

On the topic of treating the photographers behind, no comment, I don't want our reigning Olys champ to treat the photographers in that way at all. I hope no one will equate this photographers' treat as part of good skating. IMO, any skater who has a speciality in "photographers treat" loses major style points, at least with me.

Pixie:
As for the edge vs flex debate, plenty of skaters have had edges as good as and better than MK. No one, with the exception of Nicole on the spiral, comes close to Sasha's flex..."

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Pixie, I think many factors contribute to a good spiral, not just flexibility, not just edge. I have to disagree that only Sasha and Nicole have the best flex, Lucindh, Ota, Oksana, just to name a few. There is no way you can convince me that good flex alone makes the best spiral.

I think it will be fun to do a little experiment.

Take the different spiral factors and put numeric value of the importance (these values must add up to 10), then rank skaters from 1 - 10, on how well they perform these factors, and sum it up. Of course my numeric value of what is important, and my ranking of the skaters will be different from yours.

edge - I assign the importance value of 3.5
speed - I assign a value of 3
ice coverage - I assign a value of 2
extension - value of 1
amplitude - value of 0.5

I will rank Sarah
edge - I score her as 9.5 (with 10 as the best)
speed - I score her as 9
ice coverage - 9.5
extension - 6
amplitude - 9

Sum of her score 3.5 x 9.5 + 3 x 9 + 2 x 9.5 + 1 x 6 + 0.5 x 9 = 89.75 (out of a possible max of 100)

So, I have done my math homework, Pixie, let us see yours.

Sasha is a breathtaking skater and her spirals are gorgeous ( I happen to like the 180 degree split in a spiral and wish so much I could do one!). Though, I don't care for the Sasha spiral (or skid as another poster so aptly named it). I have felt for a while that Sasha is unbeatable - if she's "on". The problem is, she always beats herself by making some error whether it is on a jump, footwork, or a spin. Eventually, though, I truly believe that she'll get her head together and pull off two perfect programs. Once she conquers whatever it is that is going on in her head to mess her up - focus problems, nerves, whatever - she will be truly unstoppable.

Unfortunately, one of her deepest edges would be her INSIDE edge as she's taking off into her triple Flutz!!!!

Sasha is unbeatable when she is on...so are many other skaters when they are on.

shine said:

Sasha is unbeatable when she is on...so are many other skaters when they are on.

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I am hoping my avatar, and banners skaters be really on at nationals and worlds. Go Irina, Go AP, and Go Fumie. If Fumie wins world with my lucky numbers, you see it here first.

http://www.fumiesuguri.com/en_snaps/img/18/htm/09.jpg

"Hockey Guy" Spirals

The "hockey guy" wasn't wearing hockey skates, and here he is a month or so later. You can see the figure skates more clearly here; a much better camera was used, not to mention he's in a real skating outfit instead of ugly sweats.

And, IDLERACER, you really shouldn't post links to other people's materials without asking permission first, because you never know when they might change them out from under you!

Hi guys! I'm in way over my head here with all this talk, but I just wanted to share this photo of Sasha's outside edge. I got it from passionplus.net.... I love this photo. I love that site too. Click here to see the photo.

This photo showcases Sasha's edges very well, CartDi. I believe, I've posted this one on another thread.

Here's another great one:
http://www.windweaver.com/coi2003/sasha2003c.htm
(scroll down to see the spiral).

GORGEOUS!

These photos are GORGEOUS, and those edges are SUPERB! Thanks for posting!

Re: "Hockey Guy" Spirals

IDLERACER, you really shouldn't post links to other people's materials without asking permission first, because you never know when they might change them out from under you!

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Argh! He looks a little like the holographic doctor on "Voyager." I just noticed that when you now click on the "goofus" icon on my original post, the link takes you to a picture of Michelle Kwan not only demonstrating a graceful spiral, but also demonstrating just how much magic a wonderbra can accomplish when fitted properly.

It doesn't get much "edgier" than this:

IDLERACER said:

It doesn't get much "edgier" than this:

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Actually, if you'll compare pictures, Sasha gets better lean:

http://www.windweaver.com/coi2003/sasha91527.jpg