Graphics Reference
In-Depth Information
sprinters that accelerate quickly at the beginning of a run demonstrate a
greater degree of motion in the arms than they do once they are into their
stride.
The rising and falling of a figure during a running action is much more
pronounced than in a walk cycle. The rise during the suspension phase is
higher, and the squash results in more compression of the leg due to a bend
at the knee, locating the figure slightly lower than in a walk.
As with the walk cycle, the nature of the run determines the speed at
which the figure is moving. Furthermore, as with the walk cycle, the
speed of the run will change with the varying length and frequency of the
strides.
To aid our analysis of a running action, I have broken the movement into
the key points in the cycle. For our purposes I have limited the keyframes in
the illustration to four, though in the phased sequence that follows, where
I provide a detailed written description of the actions at the various points of
the cycle, I have included two additional phases.
FIG 5.48
Four key positions of a
run cycle.
As with the walk cycle, the phase order I present here has no distinct
beginning or end. I have started the sequence in the most obvious place (at
least it is the most obvious to me): at the moment just before the figure strides
forward and both feet leave the ground.
This sequence provides a general guide for a run cycle, but it is clear that
many variations will occur in different instances and for different types of
figures.
Phase One: The Push
•
The left leg is extended fully backward, the knee straightened and the toes
pushing against the ground, providing maximum thrust.
•
The right leg has swung forward and is bent, allowing the foot to clear the
ground. The knee extends forward of the rest of the leg.
