Fig. 1. Model structure: (A) large horse, (B) small horse, (C) goat, (D) large dog,
(E) small dog and (F) chipmunk. Joint locations, segment dimensions and mass
distributions are from photographic, video and anatomical data
(Muybridge, 1957;
Taylor et al., 1974;
Fedak et al., 1982;
Alexander, 1985;
Farley et al., 1993). All
segments are represented as rigid bodies. Pin (rotary) joints are included on
the back and neck. Each leg rotates about a pin joint at the shoulder or hip
and changes length through a prismatic (telescoping) joint at the elbow or
knee. Active hip and shoulder torques control the forward motion from stride
to stride. Motions are restricted to the sagittal plane.
