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Among the characteristics that are thought to set primate quadrupedal locomotion apart from that of nonprimate mammals are a more protracted limb posture and larger limb angular excursion. However, kinematic aspects of primate or nonprimate quadrupedal locomotion have been documented in only a handful of species, and more widely for the hind than the(More)
Several features that appear to differentiate the walking gaits of most primates from those of most other mammals (the prevalence of diagonal-sequence footfalls, high degrees of humeral protraction, and low forelimb vs. hindlimb peak vertical forces) are believed to have evolved in response to requirements of locomotion on thin arboreal supports by early(More)
It is often claimed that the walking gaits of primates are unusual because, unlike most other mammals, primates appear to have higher vertical peak ground reaction forces on their hindlimbs than on their forelimbs. Many researchers have argued that this pattern of ground reaction force distribution is part of a general adaptation to arboreal locomotion.(More)
The forelimb joints of terrestrial primate quadrupeds appear better able to resist mediolateral (ML) shear forces than those of arboreal quadrupedal monkeys. These differences in forelimb morphology have been used extensively to infer locomotor behavior in extinct primate quadrupeds. However, the nature of ML substrate reaction forces (SRF) during arboreal(More)
An understanding of the evolution of human bipedalism can provide valuable insights into the biomechanical and physiological characteristics of locomotion in modern humans. The walking gaits of humans, other bipeds and most quadrupedal mammals can best be described by using an inverted-pendulum model, in which there is minimal change in flexion of the limb(More)
Experiments were run to assess whether adult female rhesus monkeys would spontaneously learn to choose the correct (i.e. baited) of two objects on the basis of explicit behavioural cues given by the experimenter. In the first part of the study the experimenter either stood up straight with his arms by his side and fixated centrally between the two objects(More)
The locomotion of primates differs from that of other mammals in three fundamental ways. During quadrupedal walking, primates use diagonal sequence gaits, protract their arms more at forelimb touchdown, and experience lower vertical substrate reaction forces on their forelimbs relative to their hindlimbs. It is widely held that the unusual walking gaits of(More)
In this report we provide detailed data on the patterns and frequency of heel contact with terrestrial and arboreal supports in primates. These data can help resolve the question of whether African apes and humans are uniquely "plantigrade" (Gebo [1992] Am. J. Phys. Anthropol. 89:29-58; Gebo [1993a] Am. J. Phys. Anthropol. 91:382-385; Gebo [1993b](More)
One trait that distinguishes the walking gaits of most primates from those of most mammalian nonprimates is the distribution of weight between the forelimbs and hindlimbs. Nonprimate mammals generally experience higher vertical peak substrate reaction forces on the forelimb than on the hindlimb. Primates, in contrast, generally experience higher vertical(More)
Analysis of the teeth, orbital, and gnathic regions of the skull, and fragmentary postcranial bones provides evidence for reconstructing a behavioral profile of Amphipithecidae: Pondaungia, Amphipithecus, Myanmarpithecus (late middle Eocene, Myanmar) and Siamopithecus (late Eocene, Thailand). At 5-8 kg, Pondaungia, Amphipithecus, and Siamopithecus are(More)