基于有限元模型及步态分析的足底筋膜受力机制研究及刚度可调节的足弓支撑研发

Plantar fasciitis (PF) is a major public health disorder in elderly populations. PF causes chronic heel pain which may severely hinder regular activities. However, diagnosis and treatment of PF is mainly based on the experience of physicians in China. Both surgical and non-surgical treatment have their limitations, which makes PF one of the most difficult problems to heal. Therefore, there is a need to establish a body of knowledge for treatment principals for physicians. The goal of this research is to study the foot and ankle biomechanical behavior with PF and to develop a new arch support for treatment of PF. A finite element (FE) model of the foot and ankle with arch support will be established in ABAQUS to study the biomechanical behavior of the foot and ankle, the force-displacement relationship of the Plantar Aponeurosis (PA), and the relationship between the stiffness of the arch support and the foot and ankle biomechanical parameters including Plantar Aponeurosis strain, plantar pressure distributions and mid-foot metatarsal inter-joint rotation. A new arch support with tunable stiffness mechanism will then be developed for this research, to be used in loading experiment and gait analysis, to study the effect of support stiffness on biomechanical control of the foot and ankle quantitatively. Finally, the FE model validated with experiments will be used to obtain the support needs of the foot and ankle, and to develop a quantitative index for evaluating the effectiveness of the arch support for treatment of PF. This research will serve as a reference for treatment principals of PF for physicians.

足底筋膜炎是老年群体最常见的足疾之一，严重影响老年群体的生活质量。然而目前我国对于足底筋膜炎的诊断和治疗很大程度上依赖于医生的经验，手术治疗及非手术治疗效果均不是很理想，使其成为足踝外科的一大难题。因此有必要研究足底筋膜炎的发病机理及科学的治疗方法。本研究的主要目标就是通过有限元模拟及试验方法来分析足底筋膜的受力及损伤机制并研发一种新型的足弓支撑来治疗足底筋膜炎。首先在ABAQUS中建立足踝及足弓支撑精细化有限元模型，研究足踝的受力性能、足底筋膜的受力机制，及足弓支撑的刚度对足底筋膜应变、足底压力分布、中足跖骨关节转角等足踝生物力学参数之间的关系。其次研发刚度可调节的足弓支撑，通过加载试验以及步态分析试验定量研究不同的支撑刚度对足踝关键生物力学参数的控制效果。最后结合有限元分析及试验结果获取足踝的刚度需求并建立足弓支撑对足底筋膜炎疗效的定量评价指标。为足踝外科医生的诊断和治疗提供科学依据。

足底筋膜炎（俗称：脚跟痛，PF）是中老年群体常见的身体疾病/损伤，目前的诊断和治疗方法均是基于足踝外科医生的经验，诊断及治疗效果均存在很多问题。因此有必要建立足底筋膜炎科学、客观、系统的诊断及治疗方法。本项目采用有限元建模、实验验证及步态分析等方法研究了（1）足底筋膜的受力及损伤机制并阐明足底筋膜炎的生物力学表征特性；（2）为了研究“足-鞋”/“足-地面”相互作用，研发了高度可调节的矫形鞋垫/足弓支撑来研究足弓支撑高度对足底压力分布及步态等足踝生物力学参数的影响；（3）研发了三种刚度可调节的装置，在有限元模型中通过变刚度研究获得患足的支撑刚度需求；（4）建立了矫形鞋垫/足弓支撑形态、刚度、足弓高度等参数的设计方法及合适的设计区间；（5）开发了一套足踝有限元建模分析的全过程自动化快速建模技术，将建模时间从2-3年缩短至数分钟。本项目主要集中于足踝生物力学研究及矫形鞋垫/足弓支撑的设计，但是研究的方法及取得的成果也可以扩展到下肢支具及其他结构控制系统。