Effects of limb mass distribution on the ontogeny of quadrupedalism in infant baboons (Papio cynocephalus) and implications for the evolution of primate quadrupedalism

The baboons in this sample showed a shift in their kinematics as their limb mass distributions changed during ontogeny. When their limb mass was most distally concentrated (at young ages), stride frequencies were relatively low, stride lengths were relatively long, and stance durations were relatively long compared to older ages when limb mass was more proximally concentrated. These results suggest that the evolution of primate quadrupedal kinematics was tied to the evolution of grasping hands and feet.