Silver-Thorn M B, Childress D S
Marquette University, Department of Biomedical Engineering, Milwaukee, WI 53201-1881, USA.
J Rehabil Res Dev. 1997 Apr;34(2):171-86.
Finite element (FE) analysis was used to investigate the stress distribution between the residual limb and prosthetic socket of persons with transtibial amputation (TTA). The purpose of this study was to develop a tool to provide a quantitative estimate of prosthetic interface pressures to improve our understanding of residual limb/prosthetic socket biomechanics and prosthetic fit. FE models of the residual limb and prosthetic socket were created. In contrast to previous FE models of the prosthetic socket/residual limb system, these models were not based on the geometry of a particular individual, but instead were based on a generic, geometric approximation of the residual limb. These models could then be scaled for the limbs of specific individuals. The material properties of the bulk soft tissues of the residual limb were based upon local in vivo indentor studies. Significant effort was devoted toward the validation of these generic, geometric FE models; prosthetic interface pressures estimated via the FE model were compared to experimentally determined interface pressures for several persons with TTA in a variety of socket designs and static load/alignment states. The FE normal stresses were of the same order of magnitude as the measured stresses (0-200 kPa); however, significant differences in the stress distribution were observed. Although the generic, geometric FE models do not appear to accurately predict the stress distribution for specific subjects, the models have practical applications in comparative stress distribution studies.
采用有限元（FE）分析来研究经胫骨截肢（TTA）患者残肢与假肢接受腔之间的应力分布。本研究的目的是开发一种工具，以提供对假肢界面压力的定量估计，从而增进我们对残肢/假肢接受腔生物力学和假肢适配性的理解。创建了残肢和假肢接受腔的有限元模型。与先前的假肢接受腔/残肢系统有限元模型不同，这些模型并非基于特定个体的几何形状，而是基于残肢的通用几何近似。然后可以针对特定个体的肢体对这些模型进行缩放。残肢大块软组织的材料特性基于局部体内压痕研究。投入了大量精力来验证这些通用的几何有限元模型；通过有限元模型估计的假肢界面压力与在多种接受腔设计以及静态负荷/对线状态下的几名TTA患者的实验确定的界面压力进行了比较。有限元法得到的法向应力与测量应力（0 - 200 kPa）处于同一数量级；然而，观察到应力分布存在显著差异。尽管通用的几何有限元模型似乎无法准确预测特定受试者的应力分布，但这些模型在比较应力分布研究中具有实际应用价值。
