Graphics Reference
In-Depth Information
FIG 4.19
Kangaroo hopping sequence illustrating the synchronized motion of its hind legs.
weight as the rear legs are swung quickly forward. Once on the ground the
legs, along with the tail, create a balanced platform that then enables the
front legs to be swung forward. The kangaroo's strong tail offers a third point
of support when it is moving at slow speeds and provides a firm base of
support when the kangaroo is standing upright. When moving at great speed,
the kangaroo hops, using its tail to act as a counterbalance to the body. The
front legs play a very small part in the locomotion. The front legs terminate in
paws rather than feet and are far more suited to delicate manipulation than
propulsion.
Crocodiles
The crocodile is fairly typical of reptilian quadrupeds in that it holds it legs
splayed away from its body. When at rest, a crocodile's body and long tail
are supported on the ground and then lifted during the walk. To what
degree they are lifted depends on the speed of the walk. At low speeds the
body is barely lifted clear of the ground and the tail may drag. At higher
speeds the crocodile will often lift its body much higher off the ground.
The lateral rotation of the body of quadrupeds that have splayed legs is far
