基于三维膝-踝-足有限元模型的足跟痛足底压力生物力学分析

目的 通过有限元方法研究鞋垫参数变化对足跟痛患足生物力学机制的影响。方法 基于CT图像数据建立足跟痛患者足部、小腿骨骼、腓肠肌及膝关节三维有限元模型，通过改变鞋垫形状、厚度及硬度仿真计算足底压力分布及应力峰值。结果 有限元模型足底压力分布与压力测量板的足底压力分布部位大体一致，数值非常接近。与裸足站立相比，穿着平板式、半接触式和全接触式鞋垫时足跟区压力峰值分别下降20.5%、59.2%和38.4%，跖骨头区压力峰值分别下降9.9%、18.1%和46.7%。足跟痛患者足底表面足跟区和跖骨头区域压力峰值均随鞋垫常规厚度的增加而减小，并随硬度的减小而减小。结论 鞋垫参数的改变对足底压力产生显著的变化。有限元分析有助于足跟痛病因病理的了解，为临床治疗提供理论基础。
Objective To investigate the effects of insole parameter changes on biomechanical mechanism of heel pain by finite element methods. Methods The 3D finite element model of foot, crus bones, gastrocnemius muscle and knee joint was reconstructed based on CT images. The plantar pressure distribution and peak pressure were calculated by changing the shape, thickness and hardness of the insole. Results The distribution of plantar pressure calculated by the finite element model was generally consistent with that measured by the pressure plate, and the values were very close. Compared with the barefoot standing, the peak pressure of the heel was decreased by 20.5%, 59.2% and 38.4%, and that of the metatarsal head was decreased by 9.9%, 18.1% and 46.7%, with flat insole, half-contact insole and full-contact insole, respectively. For patients with heel pain, the pressure peak of the heel and the metatarsal head at plantar surface decreased with the conventional thickness of insole increasing and the hardness of insole decreasing. Conclusions The changes in insole parameters have a significant influence on the plantar pressure distribution. Finite element analysis can contribute to discovering the etiology and pathology of heel pain, so as to provide the theoretical basis for clinical treatment.