Thomason Jeffrey J, McClinchey Heather L, Faramarzi Babak, Jofriet Jan C
Department of Biomedical Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Anat Rec A Discov Mol Cell Evol Biol. 2005 Apr;283(2):366-79. doi: 10.1002/ar.a.20173.
The horse's hoof is structurally modified for its mechanical functions, but studying the functional design of internal structures is hampered by the external keratinous capsule. Finite-element analysis offers one method for evaluating mechanical function of components within the capsule, such as the laminar junction. This is the epidermodermal connection that binds the hoof wall strongly to the distal phalanx. Primary epidermal laminae (PEL), projecting inward from the wall, vary in morphology and are remodeled despite being keratinous. The aim of this study is to investigate the suggestion that remodeling of PEL is influenced by mechanical stress. Circumferential and proximodistal stress distribution and relative displacement in the laminar junction are assessed by finite-element analysis (FEA) of nine hoof models. Spacing, orientation, and curvature of PEL are assessed from sections through 47 other hooves and compared with the stress and displacement data. Significant correlations are found between laminar spacing and seven displacement and stress variables, supporting the link between stresses and remodeling. Differences in external hoof shape cause regional variation in stress magnitudes around the laminar junction. This finding is in accord with previous observations that laminar morphology is individually regionally variable. This work provides the first concrete link between mechanical behavior and laminar morphology.
马蹄在结构上经过了改造以适应其机械功能，但由于外部角质囊的存在，对内部结构功能设计的研究受到了阻碍。有限元分析提供了一种评估蹄囊内各组成部分（如板层结合处）机械功能的方法。板层结合处是将蹄壁牢固地连接到远节指骨的表皮-真皮连接。从蹄壁向内突出的初级表皮板层（PEL）形态各异，尽管是角质化的，但仍会发生重塑。本研究的目的是调查PEL重塑受机械应力影响这一观点。通过对九个蹄模型进行有限元分析（FEA），评估板层结合处的周向和近远中应力分布以及相对位移。从另外47个蹄的切片中评估PEL的间距、方向和曲率，并与应力和位移数据进行比较。发现板层间距与七个位移和应力变量之间存在显著相关性，支持了应力与重塑之间的联系。蹄的外部形状差异导致板层结合处周围应力大小存在区域差异。这一发现与之前关于板层形态在个体和区域上存在差异的观察结果一致。这项工作首次在机械行为和板层形态之间建立了具体联系。
