SI Movie 1: animation of DF=0.75, phase=25% walking model. from The grazing gait, and implications of toppling table geometry for primate footfall sequences

Animation of quadrupedal walking with duty factor = 0.75 and phase 25% (lateral sequence or ‘normal’ walking), resulting in exactly three feet in contact with the ground at all instants. The centre of mass (blue circle) is maintained above a polygon of support formed by the feet (grey triangle). The back rolls and pitches due to changes in height (black low, red high) of the hips and shoulders vaulting over those legs in contact with the ground. There is a discontinuity demanding sudden rolling and pitching at the transition to forefoot contact.