Charlie,
Thanks for the clarification on “departure” and your thoughts on this subject. I certainly agree on the Conscious equals Slow observation. Where I stumble is on the notion that learning one set of mechanics is somehow more complex, or more conscious, from another set of mechanics from the athlete’s perspective; particularly when the differences are relatively subtle.
In many fields it is usually subtle change, or a new perspective on a traditional solution that allows for the evolution and advancement of performance (re: internal combustion engine), so I am somewhat leery of leaving well enough alone being my approach before considering what mechanical advantage/disadvantage might be conferred by change.
I have to admit to scouring everything that has been discussed on this subject over the years on this site (junky) so I am not unfamiliar with the material or arguments. They always just seemed to be missing something though, which is why I have brought it up again. I thought the comments by S. Francis in this regard might spark a round of thoughtful “What ifs”.
Treble,
I don’t deny that extension exists in any of these athletes (though the degree varies). But my understanding of the concept of Triple Extension is that it happens together. If we see maximum knee extension prior to maximum hip extension, and that the angle at the knee recedes from this maximum as the stride cycle approaches maximum hip extension, then perhaps tripe extension (or the maximum expression of it) is not so very important to the maximization of sprinting at top speed.
Now if this were one of my Olympic Weightlifters, I would argue that maximum triple extension is vital, particularly because of the overwhelmingly vertical nature of the exercise. Sprinting however is a balance of vertical and horizontal forces, and the application time is so short that it somewhat negates the notion of maximums along any particular axis of force application. To me the issue becomes one of most effective force application and what tradeoffs achieving this means to the entire stride cycle (frequency, relaxation, hip height, etc.).
In this respect I see hip height as being possibly more about the balance between frequency and amplitude than it is about hip height at the bottom of the sine wave (ground contact)…within reason. In this case full triple extension vs. a slight sit could both see ground contact similarly close to occurring under BDC. The question in my mind is whether one or the other affords some sort of advantage to effective force application over the other…and if the mechanics of this might cascade, or spill over into the recovery phase (positively or negatively).
I never bought into the notion that the video evidence on Asafa was an allusion created by slow video frame rates. He is amazing as you say, but only incrementally so in terms of physical measurements of limb speed. He doesn’t represent a sudden leap to hummingbird quickness for humans. If we saw something in his movement that was different form other athletes appearing alongside him (or behind him most likely) in the same frame, it was because the movement was different.
Whether I have the knowledge of communication skills to incite some of the talented and experienced participants of this site to take another look at this issue I don’t know, but it would certainly be a conversation that I would enjoy seeing. Or maybe it really is a non-issue.
