Department of Cultural Heritage, University of Bologna, Ravenna, Italy.
Department of Anthropology, Pennsylvania State University, State College, Pennsylvania, USA.
Anat Rec (Hoboken). 2023 Jan;306(1):124-142. doi: 10.1002/ar.25010. Epub 2022 Jun 21.
The development of bipedalism is a very complex activity that contributes to shaping the anatomy of the foot. The talus, which starts ossifying in utero, may account for the developing stages from the late gestational phase onwards. Here, we explore the early development of the talus in both its internal and external morphology to broaden the knowledge of the anatomical changes that occur during early development.
The sample consists of high-resolution microCT scans of 28 modern juvenile tali (from 36 prenatal weeks to 2 years), from a broad chronological range from the Late Roman period to the 20th century. We applied geometric morphometric and whole-bone trabecular analysis to investigate the early talar morphological changes.
In the youngest group (<6 postnatal months), the immature external shell is accompanied by an isotropic internal structure, with thin and densely packed trabeculae. After the initial attempts of locomotion, bone volume fraction decreases, while anisotropy and trabecular thickness increase. These internal changes correspond to the maturation of the external shell, which is now more defined and shows the development of the articular surfaces.
The internal and external morphology of the human talus reflects the diverse load on the foot during the initial phases of the bipedal locomotion, with the youngest group potentially reflecting the lack of readiness of the human talus to bear forces and perform bipedal walking. These results highlight the link between mechanical loading and bone development in the human talus during the acquisition of bipedalism, providing new insight into the early phases of talar development.
两足行走的发展是一项非常复杂的活动，它有助于塑造足部的解剖结构。距骨在子宫内开始骨化，可能代表了从晚期妊娠阶段开始的发育阶段。在这里，我们探索距骨的内部和外部形态的早期发育，以拓宽对早期发育过程中发生的解剖变化的认识。
样本包括 28 个现代青少年距骨的高分辨率微 CT 扫描，这些距骨来自从罗马晚期到 20 世纪的广泛时间范围。我们应用几何形态测量和全骨小梁分析来研究早期距骨形态变化。
在最小的组（<6 个月）中，未成熟的外部壳伴随着各向同性的内部结构，具有薄而密集的小梁。在最初尝试运动之后，骨体积分数降低，而各向异性和小梁厚度增加。这些内部变化与外部壳的成熟相对应，现在外部壳更加明确，并显示出关节面的发育。
人类距骨的内部和外部形态反映了在双足运动的初始阶段足部承受的不同负荷，最小的组可能反映了人类距骨在承受力和进行双足行走方面尚未准备好。这些结果强调了在获得双足行走过程中，机械载荷和人类距骨骨发育之间的联系，为距骨发育的早期阶段提供了新的见解。
