School of Life Sciences, Anglia Ruskin University, Cambridge, UK.
School of Earth and Environmental Sciences, University of Manchester, Manchester, UK.
Anat Rec (Hoboken). 2023 Jan;306(1):60-78. doi: 10.1002/ar.25048. Epub 2022 Aug 25.
The growth and development of long bones are of considerable interests in the fields of comparative anatomy and palaeoanthropology, as evolutionary changes and adaptations to specific physical activity patterns are expected to be revealed during bone ontogeny. Traditionally, the cross-sectional geometry of long bones has been examined at discrete locations usually placed at set intervals or fixed percentage distances along the midline axis of the bone shaft. More recently, the technique of morphometric mapping has enabled the continuous analysis of shape variation along the shaft. Here we extend this technique to the full sequence of late fetal and postnatal development of the humeral shaft in a modern human population sample, with the aim of establishing the shape changes during growth and their relationship with the development of the arm musculature and activity patterns. A sample of modern human humeri from individuals of age ranging from 24 weeks in utero to 18 years was imaged using microtomography at multiple resolutions and custom Matlab scripts. Standard biomechanical properties, cortical thickness, surface curvature, and pseudo-landmarks were extracted along radial vectors spaced at intervals of 1° at each 0.5% longitudinal increment measured along the shaft axis. Heat maps were also generated for cortical thickness and surface curvature. The results demonstrate that a whole bone approach to analysis of cross-sectional geometry is more desirable where possible, as there is a continuous pattern of variation along the shaft. It is also possible to discriminate very young individuals and adolescents from other groups by relative cortical thickness, and also by periosteal surface curvature.
长骨的生长和发育在比较解剖学和古人类学领域具有相当大的兴趣，因为在骨骼发育过程中，预计会揭示出进化变化和对特定身体活动模式的适应。传统上，长骨的横截面几何形状是在离散位置进行检查的，这些位置通常位于骨轴中线的固定间隔或固定百分比距离处。最近，形态测量制图技术使我们能够沿着骨干连续分析形状变化。在这里，我们将这项技术扩展到现代人类群体样本中肱骨骨干的后期胎儿和产后发育的完整序列，目的是确定生长过程中的形状变化及其与手臂肌肉发育和活动模式的关系。我们使用微断层扫描对年龄在 24 周宫内到 18 岁的个体的现代人类肱骨进行了成像，并使用定制的 Matlab 脚本在多个分辨率下进行了成像。在每个 0.5%的骨干轴长增量处，以 1°的间隔沿径向矢量提取标准生物力学特性、皮质厚度、表面曲率和伪标志。还生成了皮质厚度和表面曲率的热图。结果表明，在可能的情况下，对横截面几何形状进行整体骨骼分析更为可取，因为沿着骨干存在连续的变化模式。通过相对皮质厚度，也可以通过骨膜表面曲率来区分非常年轻的个体和青少年与其他群体。
