Knuckle-walking and the problem of human origins.
D000220:Adaptation, Biological; D000818:Animals; D005075:Biological Evolution; D001696:Biomechanical Phenomena; D005384:Finger Joint; D006225:Hand / Q000033:anatomy & histology; D015186:Hominidae; D008124:Locomotion; D008954:Models, Biological; D011187:Posture; D013045:Species Specificity