Kristiaan D'Août

Learn More
It is commonly held that the major functional features of the human foot (e.g. a functional longitudinal medial arch, lateral to medial force transfer and hallucal (big-toe) push-off) appear only in the last 2 Myr, but functional interpretations of footbones and footprints of early human ancestors (hominins) prior to 2 million years ago (Mya) remain(More)
This study gives a qualitative and quantitative description of the different terrestrial locomotor modes of a group of white-handed gibbons (Hylobates lar) from the Wild Animal Park Planckendael, Belgium. The gibbons were filmed during voluntary locomotion on a grassy and smooth substrate and on a pole. These video images allowed us to define seven(More)
When gibbons travel through the forest canopy, brachiation is alternated with short bipedal bouts over horizontal boughs. We know, from previous research, that brachiation is a very efficient locomotor mode that makes use of a pendulum-like exchange of energy, but to date, nothing is known about the dynamics of hylobatid bipedalism. We wondered if gibbons(More)
Gibbons are highly arboreal apes, and it is expected that their bipedal locomotion will show some particularities related to the arboreal environment. Previous research has shown that, during hylobatid bipedalism, unsupported phases are rare and stride frequencies are relatively low. This study confirms previous findings, and we suggest that low stride(More)
Swimming movements of 7 European green frogs (Rana esculenta) were studied, starting from the detailed analysis of the speed and timing of the propulsive, glide, and recovery phases of their intermittent swimming behavior. First, the authors identified the spatiotemporal factors used by the frogs to modulate their swimming behavior. None of the gait(More)
The ostrich is highly specialized in terrestrial locomotion and is the only extant bird that is both didactyl and exhibits a permanently elevated metatarsophalangeal joint. This extreme degree of digitigrady provides an excellent opportunity for the study of phalangeal adaptation towards fast, sustained bipedal locomotion. Data were gathered in a(More)
We describe segment angles (trunk, thigh, shank, and foot) and joint angles (hip, knee, and ankle) for the hind limbs of bonobos walking bipedally ("bent-hip bent-knee walking," 17 sequences) and quadrupedally (33 sequences). Data were based on video recordings (50 Hz) of nine subjects in a lateral view, walking at voluntary speed. The major differences(More)
We collected high-resolution plantar pressure distributions of seven bonobos during terrestrial bipedal and quadrupedal locomotion (N = 146). Functional foot length, degree of hallux abduction, and total contact time were determined, and plots, showing pressure as a function of time for six different foot regions, were generated. We also studied five adult(More)
This paper illustrates how simple mechanical models based on morphological, ethological, ecological and phylogenetic data can add to discussions in evolutionary biology. Bipedal locomotion has evolved on numerous occasions in lizards. Traits that appear repeatedly in independent evolutionary lines are often considered adaptive, but the exact advantages of(More)
One of the great ongoing debates in palaeo-anthropology is when, and how, hominids acquired habitual bipedal locomotion. The newly adopted bipedal gait and the ancestral quadrupedal gait are most often considered as very distinct, with each habitual locomotor mode showing corresponding anatomical adaptations. Bonobos (Pan paniscus), along with common(More)