The Human Foot and Bipedalism: Evolutionary Adaptations for Efficient Upright Locomotion
Start Date
August 2025
End Date
August 2025
Location
ALT 303
Abstract
The human foot has undergone several key evolutionary adaptations that distinguish it from the feet of other primates and were crucial for the development of habitual bipedal locomotion. A combination of anatomical features distinguishes the human foot from that of both extant non-human primates and extinct hominin ancestors. This study explores the evolutionary significance of some of these features that include the development of foot arches, hallux alignment, toe length, and how these features relate to locomotor efficiency. Particular focus was placed on the mechanical advantage (MA) of the muscles in the plantar-flexor system, which is directly modulated, in this case, by toe length and perhaps even calcaneal robustness. Analysis of MA enables the estimation of the push-off force that a particular plantar-flexor system is able to generate. Comparisons were made of the MA of the human foot with that of several extinct hominin species (Homo neanderthalensis, Homo floresiensis, Homo naledi, Ardipithecus ramidus) and two extant great apes (Chimpanzee and orangutan). Results indicate that MA is greatest in the human plantar-flexor system, and the extinct hominin ancestors have a MA that is intermediate between humans and the living great apes.
Key Words: Bipedalism, Mechanical advantage, Hominin evolution, Locomotion, Plantarflexion, Hallux alignment, Toe length, Foot arch
The Human Foot and Bipedalism: Evolutionary Adaptations for Efficient Upright Locomotion
ALT 303
The human foot has undergone several key evolutionary adaptations that distinguish it from the feet of other primates and were crucial for the development of habitual bipedal locomotion. A combination of anatomical features distinguishes the human foot from that of both extant non-human primates and extinct hominin ancestors. This study explores the evolutionary significance of some of these features that include the development of foot arches, hallux alignment, toe length, and how these features relate to locomotor efficiency. Particular focus was placed on the mechanical advantage (MA) of the muscles in the plantar-flexor system, which is directly modulated, in this case, by toe length and perhaps even calcaneal robustness. Analysis of MA enables the estimation of the push-off force that a particular plantar-flexor system is able to generate. Comparisons were made of the MA of the human foot with that of several extinct hominin species (Homo neanderthalensis, Homo floresiensis, Homo naledi, Ardipithecus ramidus) and two extant great apes (Chimpanzee and orangutan). Results indicate that MA is greatest in the human plantar-flexor system, and the extinct hominin ancestors have a MA that is intermediate between humans and the living great apes.
Key Words: Bipedalism, Mechanical advantage, Hominin evolution, Locomotion, Plantarflexion, Hallux alignment, Toe length, Foot arch
