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These comparisons include Leg muscle moves only, not any Upper Body
moves.
see also:
comparisons for all moves of Entire Body (including both Leg and
Upper Body moves.
major move "functions"
Just after set-down, the hip-extension move raise the mass of the upper
body (building gravitational potential energy). After the ankle passes
backward underneath its hip, the knee-extension move starts to execute,
and the mass of the upper body falls forward (converting potential
energy into kinetic energy). Finally just before lift-up, the
ankle-extension move executes.
This move adds propulsive force by accelerating the mass of one side of
the upper body forward relative to the currently pushing hip, and by
increasing the speed (and thus force) of that side of the upper body
against the resistance of the air.
Or there's a different way of looking at the
leg-push: That the "origin" of the push through the foot is not its own
hip, but the opposite hip joint -- so the pelvis-twist move contributes
to the distance of that push by moving the pushing-foot-side hip
backward relative to the opposite hip.
for making very long strides on flat ground, this
function can also be used:
but this move function is not used much in normal-stride-length walking,
and not in walking up a steep hill.
another move function has slight benefit:
sub-moves + "articulations"
pushing leg
recovering leg forward-backward
There is no significant net positive contribution for
reactive backward-force in walking with continuous ground contact.
These moves make their contribution by overcoming
increased air-resistance as they move the surface areas of the upper leg
and lower leg with forward at a leg-recovery speed which is higher than
the average speed of the overall surface area of the body through the
whole stroke-cycle. But at walking speeds this contribution is small.
calculate leg+hip complexity
I choose to count the "small contribution" or
"possible contribution" moves as
adding 0.5 each to complexity.
Total propulsive moves available from legs and hips:
For analysis of de-synchronization of timing of different moves, see
page on compare
complexity of motions of entire body.
major move "functions"
The knee-flexion move applies direct propulsion work. (the
ankle-extension move is not used) The hip-extension move raises the mass
of the upper body, building gravitational potential energy for future
propulsion work.
But this function and its knee-flexion move are not used in running up a
steep hill.
The hip-extension move is already executing as the ankle passes backward
underneath its hip. Next the knee-extension move starts to execute, and
the mass of the upper body falls forward (converting potential energy
into kinetic energy). Finally just before lift-up, the ankle-extension
move executes.
This move adds propulsive force by accelerating the mass of one side of
the upper body forward relative to the currently pushing hip, and by
increasing the speed (and thus force) of that side of the upper body
against the resistance of the air.
Or there's a different way of looking at the
leg-push: That the "origin" of the push through the foot is not its own
hip, but the opposite hip joint -- so the pelvis-twist move contributes
to the distance of that push by moving the pushing-foot-side hip
backward relative to the opposite hip.
sub-moves + "articulations"
pushing leg
recovering leg forward-backward
with timing for
reactive backward-force.
Also the first two moves also make a
contribution in overcoming increased air-resistance as they move the
surface areas of the upper leg and lower leg with forward at a
leg-recovery speed which is higher than the average speed of the overall
surface area of the body through the whole stroke-cycle.
calculate leg+hip complexity
Total propulsive moves available from legs and hips:
For analysis of de-synchronization of timing of different moves, see
page on compare
complexity of motions of entire body.
major move "functions"
Casual cyclists tend to focus on the first, but elite racers make use of
all three.
Could also cover the pedaling stroke-cycle with three different
functions, such as leg-radial-press, leg-kick-backward, leg-kick-forward
-- or only two functions, leg-radial-press and leg-radial-retract. But
the number of muscle sub-moves or "articulations" remains the same.
Normally the third move usually lifts only part of the weight of the leg and
does not actually pull upward on the pedal. The remainder of the weight
of the leg is raised by upward force from the pedal (applied by the
leg-radial-press move by the other leg as downward force on other
pedal).
But in high-force situations, like a quick acceleration, or climbing
a short steep hill, sometimes the "leg-radial-retract" force exceeds the
weight of the leg and resistance from the other leg's muscles, and there
can then be some upward pulling force on the pedal.
standing
standing allows two additional move functions in the legs and hips:
sub-moves + "articulations"
Bicycling while (quietly) seated has these propulsive muscle moves
available in the hips
and legs:
-
ankle-flexion
-
ankle-extension
-
knee-flexion
-
knee-extension
-
hip-flexion
-
hip-extension
But because the motion of the legs is strongly
constrained in seated pedaling -- at the top by hips resting on seat,
and at bottom by the fixed motion of the cranks -- the ankle-flexion and
ankle-extension moves cannot add net positive work, because they have a
range-of-motion competition with the other leg moves.
Indeed pedal-angle measurements from many
elite racers shows negative ankle-extension in the downstroke and
negative ankle-flexion in the upstroke. (We might call this
"reverse ankling" or "anti-ankling".)
It is possible to design a seat-position /
crank-length configuration in which the ankle moves would add positive
work, but it is likely that such a configuration would result in lower
total power to the pedals.
So for expert technique with a "normal" seat position
and "normal" crank length, only 4 moves are available to deliver net
positive work:
-
knee-flexion
-
knee-extension
-
hip-flexion
-
hip-extension
standing
moves for the three functions shared with seated pedaling:
-
knee-flexion
-
knee-extension
-
hip-flexion
-
hip-extension
Although pedaling standing is less constrained at the top than seated
pedaling, it still seems that the ankle-extension and ankle-flexion
moves are not used by expert cyclists -- indeed the negative
ankle-extension on the downstroke might be even more pronounced.
moves for leg-sweep-outward function:
-
hip abduction
-
medial-hip-rotation
These moves are available to add positive work only if the bicycle is
leaned from side to side so that the hip joint is substantial distance
sideways from the seat, and no longer vertically above the pedals.
Perhaps it is also possible to get some net positive work from an
ankle-pronation move, but this is uncertain. There may not be enough
side-sweep range-of-motion available to get positive work from all
three different possible side-sweep articulations -- so this might be
another case for bicycle pedaling where an ankle move is ignored because
of range-of-motion conflict.
Actually even if limited to the two side-sweep moves above, there might
be significant range-of-motion competition between them.
moves for pelvis-side-tilt function:
It's not clear that elite racers actually use
this move. It might be that if move of the arms pulling on the handlebar
constrains upper body motion, then this move cannot add net positive
work -- because of range-of-motion conflict with the leg-radial-press
function. (i.e. there's only so much vertical range-of-motion available,
so any part taken by the pelvis-rocking is stolen from the arms).
calculate leg+hip complexity
Total propulsive moves available from legs and hips:
For analysis of de-synchronization of timing of different moves, see
page on compare
complexity of motions of entire body.
(also called
"kick-and-glide" or "diagonal stride")
These are the Leg moves only -- not including Upper
Body or Poling moves.
see also
The propulsive Leg+Hip muscle moves for Classic striding in
cross-country skiing with no poles are similar to
walking and running.
The Upper Body moves for Classic striding with
no poling turn out to be different from walking, but similar to running.
major move "functions"
sub-moves + "articulations"
pushing leg
simple advance with "lock-in".
special case: using climbing skins for backcountry ski
mountaineering:
In situations with very strong grip-friction
between the base of a ski with a long "tail" and the ground, an
ankle-flexion move during the early part of the leg-push might possibly
be used to add propulsive work. This would be felt as a strong upward
pressure of the top of the front half of the foot against the upper of
the ski boot. This move does not work with a normal inline skate or ice
skate or running or walking shoe, because those are too short out behind
the ankle joint to provide sufficient leverage to transmit the force to
the ground.
But we will not consider this in our measure
of complexity for typical touring or racing situations of
"cross-country" skiing.
recovering leg forward-backward
with timing for
reactive backward-force.
Also the first two moves also make a
contribution in overcoming increased air-resistance as they move the
surface areas of the upper leg and lower leg with forward at a
leg-recovery speed which is higher than the average speed of the overall
surface area of the body through the whole stroke-cycle.
calculate leg+hip complexity
Total propulsive moves available from legs and hips:
For analysis of de-synchronization of timing of different moves, see
page on compare
complexity of skiing motions of entire body.
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Leg |
d-p moves | Upper Body |-|
Phases : R 0
1 2 3
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