title: The insertions of the cruropedal muscles and implications for the locomotor evolution in primates.
abstract: We examined gross-anatomically the cruropedal muscles, which control the toe movements, in some species of insectivores, rodents and primates including humans, with a focus on the phylogenetic developments of these muscles including the distribution patterns of the tendons to the toes. Morphological changes corresponding to the phylogenetic advancement from primitive terrestrial mammals to arboreal primates were found in the short extensors and flexors, presumably in association with the enhancement of independent digital mobility. In contrast, the changes which correspond to the acquisition of terrestrial bipedality in humans were identified in the development of extensors and flexors which govern the first toe, as well as in establishment of the peroneus tertius that dorsi-flexes the talocrural joint.
authors.affiliation: Department of Biology, National Defense Medical College, Tokorozawa, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Matsumura
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Kimura
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002102:Cadaver; D007312:Eulipotyphla / Q000033:anatomy & histology / Q000502:physiology; D006614:Hindlimb; D006801:Humans; D008124:Locomotion / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology; D010802:Phylogeny; D011323:Primates / Q000033:anatomy & histology* / Q000502:physiology; D012377:Rodentia / Q000033:anatomy & histology / Q000502:physiology; D013710:Tendons / Q000033:anatomy & histology / Q000502:physiology