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Old 01-29-2007, 04:26 PM   #279
eyrie
 
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Location: Summerholm, Queensland
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Re: Baseline skillset

Quote:
Erick Mead wrote:
I believe I even wrote some while back about the nature of the human stability system having the dual eccentic hips gyrating the center of mass in a chaotic orbit shaped roughly like a warped figure-eight, citing to some balance studies as support:....Ignatius bowed out at that point in the earlier conversation, as I recall. Perhaps he will reconsider, now.
If you're talking about this study: http://arxiv.org/PS_cache/cond-mat/pdf/9908/9908185.pdf, I bowed out then because I could not fathom how you arrived at a conclusion of "dual eccentric hip gyrating the center of mass in a chaotic orbit shaped roughly like a warped figure-eight".

If you're referring to Figure 1. in that study, which plots the upper body's random meandering path in the plane of the anteroposterior (front-to-back) coordinate and mediolateral (side-to-side) coordinate over one minute.... I still don't see how you inferred that such a random chaotic front-to-back and side-to-side swaying (as in like a pendulum) as gyrational motion (i.e rotation on an axis) - much less a "figure of eight".

I'm going to avoid the math, coz like George, my math sux... but from what I've read and understand, the human balance system uses strategies based on simple harmonics - linear oscillations - not rotational oscillation.

But then again, we're talking about baseline skills and how to develop these baseline skills. So to me, anything discussing balance coping strategies, reeling silk, and gyrational motion are way off-base.

I believe Nick Gudge frequents Aikiweb, and it would be interesting to hear his opinion.

Meanwhile, I remain bowed out of that tangent discussion...

Last edited by eyrie : 01-29-2007 at 04:29 PM.

Ignatius
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