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Compare complexity of other motionsWalkingWalking with continuous ground contact has no upper body moves that add net positive propulsive work. This is because the work from the acceleration and from the deceleration components are equal and opposite -- and for moves above the hips, both parts are equally transmitted to the ground. So any upper body move in walking is self-cancelling. de-synchronization of timing among movesAll propulsive moves are simply sequential. Timing of leg-recovery or arm-swing relative to main leg-push is irrelevant to propulsive work (but might make a difference for balance). No significant timing de-synchronization points. calculate entire-body complexityResults from Leg+Hip complexity:
Total propulsive moves available from entire body:
RunningRunning has some upper body moves that can add net positive propulsive work. How come these moves work for running but not for walking? The key difference is that in the running stroke-cycle there is a phase where both feet are off the ground at the same time. The "trick" is to time the acceleration / deceleration segments of an upper body move so that the positive forward-backward reactive force comes while some foot is on the ground and the negative reactive force comes while both feet are up in the air. So the positive is transmitted into forward-propulsion, but the negative is not. see more detail on phases and timing coordination in running Possibly there could be a positive contribution from up-down reactive force, but the obvious upper body up-down moves have negative impacts on forward-backward reactive force. major move "functions"
a portion of another move function has slight benefit:
sub-moves + "articulations"upper body forward-backward(with timing for reactive backward-force)
de-synchronization of timing among movesI have not surveyed the latest experimental observations analysis of the subtleties of the running stroke-cycle, but here's my attempt to provide a numerical estimate of the complexity of its timing coordination, for the sake of comparison. My analysis of the stroke-cycle shows these points where the amount of propulsive work is impacted by the accuracy of de-synchronization:
The easier timing to learn is to synchronize the start of the arm-swing-forward move with the start of the leg-recovery move to bring the opposite leg forward -- (following the old advice to synchronize the arm moves with the opposite-side leg) -- which is sufficent to gain some work from the arm-swing-forward move. But not the maximum work.
The easier timing to learn is to synchronize the stopping of the arm-swing-backward move with the stopping of the opposite leg's "follow-through" after its leg-kick-backward move (following the old advice to synchronize the arm moves with the opposite-side leg). But that easy timing does not generate any propulsive work from the arm-swing-backward move. It also helps to start and accelerate the arm-swing-backward move before the set-down of the opposite foot -- but my current guess is that that timing is mostly automatic and natural. calculate entire-body complexityResults from Leg+Hip complexity:
Upper body moves:
Total propulsive moves available from entire body:
CyclingseatedBicycling while remaining (quietly) seated prevents significant contribution of upper body muscles. standingAdditional upper body muscle moves are available mainly when pedaling standing:
There's a tricky distinction to be made with the "pull handlebar upward" move: Whether (a) to pull statically ("isometric") to constrain the upper body and hip from moving upward; or (b) to pull with motion in the arm, to push the upper body and hip actually downward some small distance. (a) increases power to the crank by improving mechanical efficiency: more of the force of the main leg-radial-press down-push goes directly immediately into the pedal, rather than into adding potential energy to the mass of the upper body which will be used to add downward force to the next pedal stroke. (b) might add power by adding Work to the downstroke. But perhaps there is a range-of-motion conflict between the positive arm-pull and the main leg down-push? The two "pulling the handlebar toward the side" moves tend to tilt the bike to the side, which tends to move the pedal upward against the pushing leg -- which increases the pushing force between the foot and the pedal. At low cadences while standing, it might also be possible to add some positive work by using the arms to pull the torso and hips forward through the start of the downstroke. But this does not seem productive for skilled and well-trained riders in typical riding situations, so I'm going to ignore it for now. At low cadences while standing, it might also be possible to derive some positive work from well-timed vertical "bouncing" of the upper body, which might be enhanced by some Torso up-down moves. But this does not seem productive for skilled and well-trained riders in typical riding situations, so I'm going to ignore it for now. de-synchronization of timing among movesI have not surveyed the latest experimental observations analysis of the subtleties of the cycling stroke-cycle, but here's my attempt to provide a numerical estimate of the complexity of its timing coordination, for the sake of comparison. My analysis of the stroke-cycle shows these points where the amount of propulsive work is impacted by the accuracy of de-synchronization:
I think there's a temptation to delay the start of lifting the toe up with the ankle-flexion sub-move -- and so miss the opportunity for maximum overlap between the two muscle moves -- instead of starting the upward-lifting immediately as the pedal reaches its lowest point. which yields a total of 1 timing de-synchronization point. calculate entire-body complexityResults from Leg+Hip complexity:
Upper Body moves -- for cycling standing:
Total propulsive moves available from entire body:
Cycling with "Tacking"
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To send us questions or comments about this website, see the contact information -- -- Homepage is www.roberts-1.com/skate |
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© Copyright 2004-2005 Kenneth S. Roberts |
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