The relationship between limb-segment proportions and joint kinematics for the hind limbs of quadrupedal mammals

Film sequences were used to measure functional hind limb-segment proportions and joint angles at successive stages of walking strides for 22 species of quadrupedal mammals from five orders. Similar data were obtained from three trotting dogs. For each animal, nine Fourier series coefficients describing the movement of each of the hip, hock and ankle joints were obtained. Multivariate statistical analysis of these coefficients revealed that animals with similar limb-segment proportions move their joints in similar ways. However, it should be noted that animals with similar leg-segment proportions also tended to be phylogenetically related. Most of the discriminatory power was between animals of different stances (plantigrade, digitigrade or unguligrade) and between walking and trotting.