Graphics Reference
In-Depth Information
drop again as it assists in extending the reach of the leg. The forward momentum
continues and the foot is finally planted on the ground. The animal's weight is
then supported by this leg, which also begins to assist in the animal's balance.
Phase Three
At the beginning of this phase the foot is planted flat on the ground and
placed well ahead of the body, with the leg being held straight at the elbow
and the wrist. As the animal continues to move forward, the leg now enters
a supporting phase and increasingly takes the weight of the animal. The leg
remains locked throughout this phase as it rotates at the wrist to an upright
position. The shoulder rises again to its highest position as the foot passes
directly beneath it. For the first time in the cycle, force is applied by this leg,
which makes this phase the first part of the duty factor for this leg. The leg at
this stage uses a pulling action to provide forward motion. The leg completes
this phase of the movement with the shoulder located directly above the foot.
The opposite front leg is now in the passing position.
Phase Four
This phase starts with the leg locked and completely upright. There is a
rotation at the wrist and the shoulder is moving forward and dropping slightly
FIG 4.25
Foreleg of quadruped during forward stride of a walk cycle.
