Marchi Damiano
Department of Biological Anthropology and Anatomy, Duke University, 05 Bio. Sci. Bldg., Science Drive, Box 90383, Durham, NC 27708-0383, USA.
J Hum Evol. 2005 Dec;49(6):743-61. doi: 10.1016/j.jhevol.2005.08.002. Epub 2005 Oct 10.
Cheiridia are valuable indicators of positional behavior, as they directly contact the substrate, but systematic comparison of the structural properties of both metacarpals and metatarsals has never been carried out. Differences in locomotor behavior among the great apes (knuckle-walking vs. quadrumanous climbing) can produce biomechanical differences that may be elucidated by the parallel study of cross-sectional characteristics of metacarpals and metatarsals. The aim of this work is to study the cross-sectional geometric properties of these bones and their correlation with locomotor behavior in large-bodied hominoids. The comparisons between bending moments of metacarpals and metatarsals of the same ray furnished interesting results. Metacarpals III and especially IV of the knuckle-walking African apes were relatively stronger than those of humans and orangutans, and metatarsal V of humans was relatively stronger than those of the great apes. Interestingly, the relative robusticity of the metacarpal IV of the quadrumanous orangutan was between that of the African apes and that of humans. The main conclusions of the study are: 1) cross-sectional dimensions of metacarpals and metatarsals are influenced by locomotor modes in great apes and humans; 2) interlimb comparisons of cross-sectional properties of metacarpals and metatarsals are good indicators of locomotor modes in great apes and humans; and 3) the results of this study are in accord with those of previous analyses of plantar pressure and morphofunctional traits of the same bones, and with behavioral studies. These results provide a data base from which it will be possible to compare the morphology of the fossils in order to gain insight into the locomotor repertoires of extinct taxa.
指节垫是位置行为的重要指标，因为它们直接与底物接触，但从未对掌骨和跖骨的结构特性进行过系统比较。大型猿类（指关节行走与四足攀爬）之间运动行为的差异会产生生物力学差异，这可能通过对掌骨和跖骨横截面特征的平行研究来阐明。这项工作的目的是研究这些骨骼的横截面几何特性及其与大型类人猿运动行为的相关性。同一射线的掌骨和跖骨弯矩之间的比较得出了有趣的结果。指关节行走的非洲猿类的第三掌骨，尤其是第四掌骨，比人类和猩猩的掌骨相对更强壮，而人类的第五跖骨比大型猿类的相对更强壮。有趣的是，四足行走的猩猩的第四掌骨的相对粗壮程度介于非洲猿类和人类之间。该研究的主要结论是：1）掌骨和跖骨的横截面尺寸受大型猿类和人类运动模式的影响；2）掌骨和跖骨横截面特性的肢体间比较是大型猿类和人类运动模式的良好指标；3）这项研究的结果与先前对同一骨骼的足底压力和形态功能特征的分析结果以及行为研究结果一致。这些结果提供了一个数据库，从中可以比较化石的形态，以便深入了解已灭绝类群的运动方式。
