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Updated: Aug 5, 2026
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Automated Joint Space Detection Improves Bone Segmentation Accuracy
Published on: November 28, 2025
Humans and platyrrhines share a pattern of articular variance
Haley Horbaly1,2, Liam Zachary3
1Department of Health and Human Performance, Congdon School of Health Sciences, High Point University, High Point, North Carolina, USA.
Anatomical Record (Hoboken, N.J. : 2007)
|July 26, 2026
Summary
Convex joint surfaces like the distal humerus show less shape variation than concave surfaces such as the proximal ulna. This pattern, observed in New World monkeys, suggests conserved developmental or biomechanical constraints in joint morphogenesis.
Area of Science:
- Evolutionary biology
- Comparative anatomy
- Biomechanics
Background:
- Previous research identified constrained variance in human convex joint surfaces compared to concave ones.
- Joint morphogenesis is influenced by biomechanical factors, but the generalizability of variance patterns across species is unclear.
Purpose of the Study:
- To test if the biased variance pattern in articular shape is unique to humans or a generalizable phenomenon.
- To investigate the humeroulnar joint in New World monkeys (Platyrrhini) to assess conserved joint constraints.
Main Methods:
- Analysis of 3D geometric morphometric landmark data from 84 adult platyrrhine humeroulnar joints.
- Phylogenetic comparative analyses and two-block partial least squares to assess shape covariance.
- Comparison of morphological variance between distal humeri and proximal ulnae.
Main Results:
- Significant phylogenetic signal was found in distal humeral and proximal ulnar articular shape.
- Strong covariance between the distal humerus and proximal ulna was demonstrated.
- Distal humeri consistently showed significantly lower morphological variance than proximal ulnae.
Conclusions:
- The pattern of constrained variance in convex articular surfaces is not unique to humans.
- This suggests shared underlying developmental or biomechanical mechanisms in joint morphogenesis across diverse primate locomotor strategies.
- Comparative variance analysis is a valuable tool for inferring joint morphogenesis processes.
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