Publications [#330391] of Daniel O. Schmitt

Papers Published

1. Demes, B; Larson, SG; Stern, JT; Jungers, WL; Biknevicius, AR; Schmitt, D, The kinetics of primate quadrupedalism: "hindlimb drive" reconsidered, Journal of Human Evolution, vol. 26 no. 5-6 (May, 1994), pp. 353-374, Elsevier BV [doi]
   (last updated on 2024/04/23)

   Abstract:
   Since Kimura et al.'s (1979) analysis of ground reaction forces during quadrupedal walking, primates are commonly pictured as being "hindlimb driven" compared to "forelimb driven" nonprimate mammals. Hindlimb dominance in primates has subsequently been interpreted as a preadaptation to human bipedalism. However, given its considerable influence, surprisingly little data are available to support this putative contrast in limb dominance. In this reconsideration of locomotor kinetics in primates, we have collected force plate data on two chimpanzees, one orangutan, two vervet monkeys, and two cats for a range of gaits and speeds. The peak vertical forces acting on the limbs as well as the braking and propulsive impulses exerted by the limbs are examined. Forces and impulses are highly variable and change with speed, gait, and the differential use of asynchronously or asymmetrically placed limbs. Peak vertical forces increase with speed. The faster gaits (trot, gallop) have, on the average, higher forces than the walk. However, there is no major change in force magnitudes at gait transitions. The mean vertical forces are higher on the hindlimbs than on the forelimbs of the primates. This difference is most pronounced in the suspensory orangutan and least pronounced in the quadrupedal vervets. Cats, on the other hand, generate higher forelimb than hindlimb vertical forces. Although our results support the overall conclusion of Kimura et al. (1979) that peak vertical forces are relatively low on the primate forelimb, they also show some variation most probably related to locomotor mode. In the majority of primate cases, the major propulsive thrust is also generated by the hindlimbs. However, in the galloping vervets, the trailing limbs are propulsive and the leading limbs braking, no matter whether these are forelimbs or hindlimbs. A similar, although less pronounced, asymmetry between trailing and leading limbs was observed in a galloping chimpanzee. Not only are primates variable with regard to the roles of the limbs in propulsion, they are also not unique among mammals in being predominantly hindlimb driven. Our cats, as well as all other nonprimate mammals so far analysed, generate greater propulsive thrust with their hindlimbs; i.e. they are also "hindlimb driven". © 1994 Academic Press. All rights reserved.