<div class="csl-bib-body">
<div class="csl-entry">Dunmore, C., Bachmann, S., Kivell, T., & Skinner, M. (2025, March 13). <i>Trabecular structure of extant hominid trapezia reflects habitual thumb use</i> [Conference Presentation]. 94th Annual Meeting of the American Association of Biological Anthropologists, Baltimore, United States of America (the). http://hdl.handle.net/20.500.12708/216291</div>
</div>
-
dc.identifier.uri
http://hdl.handle.net/20.500.12708/216291
-
dc.description.abstract
The trapezium articulates with the base of thumb and is thus a critical component of thumb mobility and stability. In the modern human trapezium, relatively large and flat first metacarpal (Mc1) and coronally-oriented second metacarpal (Mc2) articular facets are part of a suite of morphological adaptations thought to enable forceful thumb opposition during pad-to-pad precision grips, to the exclusion of other extant hominids. Aspects of trapezial morphology have been used to infer tool-use in fossil hominins; however, we have comparatively less understanding of how the trapezium is loaded in non-human hominids.
As trabecular bone can (re)model in response to mechanical loading over an individual’s lifetime, it may provide additional functional information about thumb loading and use in these extant apes. Canonical holistic morphometric analysis (cHMA) is used to statistically compare the distribution of trabecular bone density (BV/TV) across Homo sapiens, (n=10), Pan paniscus, (n=10), Pan troglodytes, (n=10), Gorilla gorilla, (n=10), and Pongo sp. (n=7).
Homo sapiens has high BV/TV under the radial portion of the Mc1 facet and scaphoid facet, consistent with habitual loading from an abducted thumb during forceful thumb opposition. Gorilla shows high BV/TV under the ulnar portion of Mc1 facet that extends through to the Mc2 facet, consistent with habitual loading from an adducted thumb, such as during pad-to-side grips. Both species of Pan, and Pongo, possess spatially homogeneous trabeculae throughout the trapezium, suggesting less stereotypical loading of the thumb. These functional signals provide a broader comparative context with which to interpret fossil hominin thumb use.
en
dc.description.sponsorship
Europäischer Forschungsrat (ERC)
-
dc.language.iso
en
-
dc.subject
Bone morphology
en
dc.subject
evolutionary anthropology
en
dc.subject
Thumb
en
dc.title
Trabecular structure of extant hominid trapezia reflects habitual thumb use
en
dc.type
Presentation
en
dc.type
Vortrag
de
dc.contributor.affiliation
Max Planck Society, Germany
-
dc.relation.grantno
819960
-
dc.type.category
Conference Presentation
-
tuw.project.title
Pathways to humanity: Adaptive niche diversity at the origins of the human lineage
