Lukova Andrea, Bachmann Sebastian, Synek Alexander, Pahr Dieter H, Kilbourne Brandon, Dunmore Christopher J, Kivell Tracy L, Skinner Matthew M
Department of Human Origins, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Institute of Lightweight Design and Structural Biomechanics, Wien, Austria.
Am J Biol Anthropol. 2025 Jul;187(3):e70084. doi: 10.1002/ajpa.70084.
Extant humans and non-human apes are characterized by diverse locomotor and postural behaviors, resulting in different joint loading patterns. These behaviors influence trabecular bone, which responds to mechanical loading and joint posture. While prior studies have examined femoral trabecular structure, this study is the first to assess trabecular architecture in the proximal tibia across extant hominoids to evaluate how differences in joint use and posture are reflected in tibial morphology.
We analyze trabecular structure in the proximal tibiae of Homo sapiens (n = 25), Gorilla (n = 13), Pan troglodytes (n = 15) and Pongo sp. (n = 7). Each tibia was scanned using high-resolution microtomography, and cortical and trabecular bone were isolated from each other. Canonical holistic morphometric analysis was used to quantify trabecular bone volume fraction and degree of anisotropy. Spatial distributions of these variables were compared across taxa using principal component analysis, and group differences were assessed with multivariate analysis of variance and pairwise tests.
Results show that trabecular bone volume and anisotropy reflect habitual knee posture: extended in bipedal Homo, and flexed in non-human apes. In Gorilla, males exhibit more extended knee use than females, while no significant sex differences were observed in Homo or Pan (sex differences in Pongo were not tested due to sample limitations).
We demonstrate that the trabecular structure of the proximal tibia is consistent with habitual locomotor loading in extant hominids, which provides the comparative context to interpret knee posture, biomechanical loading, and predominant locomotor behaviors in fossil hominids.
现存人类和非人类猿类具有多样的运动和姿势行为，导致不同的关节负荷模式。这些行为会影响松质骨，松质骨会对机械负荷和关节姿势做出反应。虽然先前的研究已经考察了股骨的小梁结构，但本研究首次评估了现存类人猿近端胫骨的小梁结构，以评估关节使用和姿势的差异如何反映在胫骨形态上。
我们分析了智人（n = 25）、大猩猩（n = 13）、黑猩猩（n = 15）和猩猩属（n = 7）近端胫骨的小梁结构。使用高分辨率显微断层扫描对每根胫骨进行扫描，并将皮质骨和松质骨彼此分离。采用规范的整体形态计量分析来量化松质骨体积分数和各向异性程度。使用主成分分析比较这些变量在不同分类群中的空间分布，并通过多变量方差分析和成对检验评估组间差异。
结果表明，松质骨体积和各向异性反映了习惯性的膝关节姿势：两足行走的人类中膝关节伸展，非人类猿类中膝关节屈曲。在大猩猩中，雄性比雌性表现出更多的膝关节伸展使用，而在人类或黑猩猩中未观察到显著的性别差异（由于样本限制，未对猩猩的性别差异进行测试）。
我们证明，近端胫骨的小梁结构与现存原始人类的习惯性运动负荷一致，这为解释化石原始人类的膝关节姿势、生物力学负荷和主要运动行为提供了比较背景。
