Chimpanzee bipedalism: cineradiographic analysis and implications for the evolution of gait.
Bipedal chimpanzees reorient the pelvis to achieve an upright posture but retain the same pattern of femoral flexion and extension as in quadrupedal walking. Major differences from human gait are the abducted, relatively more flexed excursion of the femur and the timing of pelvic tilt, which raises during the swing phase. The femoral head morphology in the fossil hominid Australopithecus robustus is evidence of an approximately vertical excursion of the femur in contrast to the adducted pattern of modern man and the abducted pattern of chimpanzees.
D000818:Animals; D000843:Ankle Joint; D005075:Biological Evolution; D002933:Cineradiography; D005269:Femur / Q000033:anatomy & histology / Q000502:physiology; D005270:Femur Head / Q000033:anatomy & histology; D005684:Gait; D006621:Hip Joint; D006801:Humans; D007719:Knee Joint; D002679:Pan troglodytes / Q000033:anatomy & histology / Q000502:physiology*; D010384:Pelvic Bones / Q000033:anatomy & histology / Q000502:physiology; D011187:Posture