Table1_Human calcaneal variation relative to subsistence strategy, activity level, and footwear.DOCX

Lower limb cortical and trabecular bone varies with human behavior, leading to suggestions that activity level decreases have contributed to a more gracile skeleton. Similar trends are likely present in calcaneal morphology due to its locomotor role during heel strike. Such relationships exist in calcaneal trabecular structure; however, they have yet to be investigated in external morphology. Here entire external calcaneal shape is analyzed among three human populations that vary in subsistence strategy, activity level, and footwear use (n = 93) to investigate how calcaneal morphology varies relative to these factors. Calcanei were either surface scanned or micro-CT scanned. Calcaneal external shape was analyzed using a sliding semilandmark analysis with 1,007 semilandmarks. Semilandmarks were allowed to slide along tangent vectors or planes to minimize the bending energy of the thin plate spline interpolation function relative to an updated Procrustes average. Final landmark configurations underwent a Generalized Procrustes Analysis. Shape variation of Procrustes coordinates was summarized using principal components analysis (PCA). Procrustes distances between the average calcaneus of each population were calculated, and resampling statistics run to test for significant differences. The three populations exhibit significantly different calcaneal morphologies (p

下肢皮质骨和骨小梁的形态随人类行为而变化，这暗示了活动水平降低可能导致了骨骼的更加优雅。由于跟骨在足跟着地过程中的运动学作用，类似的趋势很可能也存在于跟骨形态学上。这样的关系存在于跟骨的骨小梁结构中；然而，它们在外部形态学方面尚未得到研究。本研究对三个在生计策略、活动水平和鞋类使用方面存在差异的人类群体（n = 93）的跟骨外部形态进行了分析，以探究跟骨形态学相对于这些因素的变化。跟骨要么进行表面扫描，要么进行微CT扫描。通过使用包含1,007个半标志点的滑动半标志分析方法，对跟骨的外部形状进行了分析。半标志点被允许沿着切向向量或平面滑动，以最小化相对于更新后的普罗克鲁斯特平均的薄板样条插值函数的弯曲能量。最终标志点的配置经历了广义普罗克鲁斯特分析。使用主成分分析（PCA）总结了普罗克鲁斯特坐标的形状变化。计算了每个群体平均跟骨之间的普罗克鲁斯特距离，并运行重采样统计以测试是否存在显著差异。三个群体表现出显著不同的跟骨形态学（p