https://www.frontiersin.org/articles/10.3389/fbioe.2021.760486/full
Comparative Functional Morphology of Human and Chimpanzee Feet Based on Three-Dimensional Finite Element Analysis
Front. Bioeng. Biotechnol., 13 January 2022

zTo comparatively investigate the morphological adaptation
of the human foot for achieving robust and efficient bipedal
locomotion, we develop three-dimensional finite element
models of the human and chimpanzee feet. Foot bones and the
outer surface of the foot are extracted from computer
tomography images and meshed with tetrahedral elements. The
ligaments and plantar fascia are represented by tension-only
spring elements. The contacts between the bones and between
the foot and ground are solved using frictionless and
Coulomb friction contact algorithms, respectively.
Physiologically realistic loading conditions of the feet
during quiet bipedal standing are simulated. Our results
indicate that the center of pressure (COP) is located more
anteriorly in the human foot than in the chimpanzee foot,
indicating a larger stability margin in bipedal posture in
humans. Furthermore, the vertical free moment generated by
the coupling motion of the calcaneus and tibia during axial
loading is larger in the human foot, which can facilitate
the compensation of the net yaw moment of the body around
the COP during bipedal locomotion. Furthermore, the human
foot can store elastic energy more effectively during axial
loading for the effective generation of propulsive force in
the late stance phase. This computational framework for a
comparative investigation of the causal relationship among
the morphology, kinematics, and kinetics of the foot may
provide a better understanding regarding the functional
significance of the morphological features of the human
foot.

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Op maandag 12 juni 2023 om 06:46:04 UTC+2 schreef Primum Sapienti:

https://www.frontiersin.org/articles/10.3389/fbioe.2021.760486/full Comparative Functional Morphology of Human and Chimpanzee Feet Based on Three-Dimensional Finite Element Analysis
Front. Bioeng. Biotechnol., 13 January 2022
To comparatively investigate the morphological adaptation
of the human foot for achieving robust and efficient bipedal
locomotion, we develop three-dimensional finite element
models of the human and chimpanzee feet. Foot bones and the
outer surface of the foot are extracted from computer
tomography images and meshed with tetrahedral elements. The
ligaments and plantar fascia are represented by tension-only
spring elements. The contacts between the bones and between
the foot and ground are solved using frictionless and
Coulomb friction contact algorithms, respectively.
Physiologically realistic loading conditions of the feet
during quiet bipedal standing are simulated. Our results
indicate that the center of pressure (COP) is located more
anteriorly in the human foot than in the chimpanzee foot,
indicating a larger stability margin in bipedal posture in
humans. Furthermore, the vertical free moment generated by
the coupling motion of the calcaneus and tibia during axial
loading is larger in the human foot, which can facilitate
the compensation of the net yaw moment of the body around
the COP during bipedal locomotion. Furthermore, the human
foot can store elastic energy more effectively during axial
loading for the effective generation of propulsive force in
the late stance phase. This computational framework for a
comparative investigation of the causal relationship among
the morphology, kinematics, and kinetics of the foot may
provide a better understanding regarding the functional
significance of the morphological features of the human foot.

Thanks a lot, this paper says we can walk & run bipedally... :-DDD
It perfectly confirms our view of Homo's evolution:
schematically (for simple-minded African savanna runners):
-- Pliocene Homo, from Africa to Java, google "aquarboreal": wading+climbing, -- early-Pleist.archaic Homo, google "pachyosteosclerosis": wading+diving, -- late-Pleistocene Homo sapiens, see paper above: wading+walking.
:-)


Already caught your antelope, Primum?

Humans vs Pan evolved soft noses & poor olfaction:
only *incredible* imbeciles still assume their Pleist.ancestors hunted antelopes on Afr.savannas.

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Humans and Chimps share a common ancestors. All the differences
between humans & Chimps evolved AFTER that common ancestor.

That common ancestor was bipedal.

The LCA had a hand that looked more like ours than a Chimps,
and it's anatomy reflected it's bipedalism... It looked like Homo
not Pan.






-- --

https://jtem.tumblr.com/post/721153190279643136

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Op maandag 26 juni 2023 om 06:19:21 UTC+2 schreef JTEM is so reasonable:

Humans and Chimps share a common ancestors. All the differences
between humans & Chimps evolved AFTER that common ancestor.
That common ancestor was bipedal.
The LCA had a hand that looked more like ours than a Chimps,
and it's anatomy reflected it's bipedalism... It looked like Homo
not Pan.

Yes, at least: its hands & feet: IIRC, fetal chimps have humanlike feet. Hominoid evolution isn't so difficult: even kudu runners can understand :-D
- wading-climbing Mio-Pliocene Hominoidea, google “aquarboreal”,
- wading-diving early-Pleistocene Homo, e.g. H.erectus, google “pachyosteosclerosis”,
- wading-walking late-Pleistocene Homo, google “gondwanatalks Verhaegen Bonne”,
https://www.gondwanatalks.com/l/the-waterside-hypothesis-wading-led-to-upright-walking-in-early-humans/

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