Quadrupedal locomotor movements in monkeys (M. Fuscata) on a treadmill: kinematic analyses.

Three adult Japanese monkeys (M. fuscata: body weights 4.5-8.5 kg) were trained to walk quadrupedally on a surface of a moving treadmill (walking length and width: 150 cm and 60 cm, treadmill speed: 0.4-1.7 m s-1. At any different constant treadmill velocity, the monkeys exhibited a diagonal pattern of locomotor movements. Side views of locomotor patterns were photographed (10 frames s-1 and videotaped (250 frames s-1. Depictions of representative locomotor patterns and stick figures of forelimb, hindlimb and trunk movements were made from the serial photographs and videotapes, respectively. Similarities and differences in the kinematics of non-human primate locomotor movements are discussed in relation to those of subprimate terrestrial animals.