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Mechanical loading of primate fingers on vertical rock surfaces

Everett, Michael C., Elliott, Marina C., Gaynor, David, Hill, Austin C., Syeda, Samar M., Casana, Jesse, Zipfel, Bernhard, DeSilva, Jeremy M, Dominy, Nathaniel J. (2021) Mechanical loading of primate fingers on vertical rock surfaces. South African Journal of Science, 117 (11/12). ISSN 0038-2353. E-ISSN 1996-7489. (doi:10.17159/sajs.2021/10409) (KAR id:93407)

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Mechanical loading of finger bones (phalanges) can induce angular curvature, which benefits arboreal primates by dissipating forces and economising the recruitment of muscles during climbing. The recent discovery of extremely curved phalanges in a hominin, Homo naledi, is puzzling, for it suggests life in an arboreal milieu, or, alternatively, habitual climbing on vertical rock surfaces. The importance of climbing rock walls is attested by several populations of baboons, one of which uses a 7-m vertical surface to enter and exit Dronkvlei Cave, De Hoop Nature Reserve, South Africa. This rock surface is an attractive model for estimating the probability of extreme mechanical loading on the phalanges of rock-climbing primates. Here we use three-dimensional photogrammetry to show that 82–91% of the climbable surface would generate high forces on the flexor tendon pulley system and severely load the phalanges of baboons and H. naledi. If such proportions are representative of vertical rock surfaces elsewhere, it may be sufficient to induce stress-mitigating curvature in the phalanges of primates.

Item Type: Article
DOI/Identification number: 10.17159/sajs.2021/10409
Uncontrolled keywords: human evolution, locomotion, climbing, suspension, bone curvature
Divisions: Divisions > Division of Human and Social Sciences > School of Anthropology and Conservation
Depositing User: Samar Syeda
Date Deposited: 24 Feb 2022 21:56 UTC
Last Modified: 25 Feb 2022 09:56 UTC
Resource URI: (The current URI for this page, for reference purposes)
Everett, Michael C.:
Elliott, Marina C.:
Gaynor, David:
Hill, Austin C.:
Syeda, Samar M.:
Casana, Jesse:
Zipfel, Bernhard:
DeSilva, Jeremy M:
Dominy, Nathaniel J.:
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