外部载荷致第一跖趾关节形变的生物力学机理研究

Metatarsal-phalangeal joint （MPJ） deformation caused by external loading becomes an endanger issue of women's health. Long-time plantar flexion posture was generally considered as precipitating factor.However, the mechanical theory about MPJ joint deformity is still not clear. Our previous studies have found that some high intensity foot action in plantar flexion status might relate to MPJ deformation. This project plans to carry out a serious of biomechanical experiments including of foot-shoe pressure distribution pattern, lower extremity muscle elcetrical signals and three-dimensional contact force during high intensity exercise on subjects with different deformtion of the first MPJ. Meanwhile, detailing three-dimensional finite element models of foot would be developed at the same time. Combining with the biomecahnical measured loading data,foot internal loading character analysising through finite element methods for the sake of revealing mechanism of the first MPJ deformation. The achievement of this research could enrich the biomechanical theory about MPJ deformation, thereby anobjective pathological mechanical theory evidence can be provided for the classification of the MPJ trauma, the choice of the treatment and the techonolgy of computational recreation research pattern.

因外部载荷致足第一跖趾关节形变为危害女性健康的重要问题。虽然已认可高鞋跟等引起的人体提踵姿态对第一跖趾关节形变产生的诱发因素，但如何导致此关节形变的力学成因尚未清晰。我们前期研究已发现提踵状态下的某些大强度动作与跖趾关节变形有一定联系。本研究将通过不同程度第一跖趾关节形变人群的生物力学测试，利用三维有限元分析获得第一跖趾关节在不同姿态加载不同方向、强度的负荷后的力学反应，还将运用表面肌 电、足底压力、动态动作捕捉等手段，对不同程度第一跖趾关节形变被试进行运动学机能研究，力图阐明第一跖趾关节形变的力学机理，从而完善该关节因外部载荷发生形变的理论研究，为临床上随后一系列的评估标准、康复策略、或重建技术等提供理论依据。

外部载荷导致第一跖趾关节形变的问题日益凸显，在女性人群中尤为突出。被动提踵刺激被普遍认为是该形变的主要诱导因素。本研究通过对健康足、轻度形变足及踇外翻足女性在高跟状态下步行、慢跑及快跑的运动生物力学测试，探究下肢关节的运动特征；通过CT断层扫描及Mimics逆向重建三维CAD足部模型，有限元分析不同状态下跖骨的应力，结合实验压力数据进行对比验证。结果与结论：鞋跟高度及穿着习惯对下肢关节运动的影响主要在踝、膝关节，且两关节的运动幅度也受穿着习惯和步速(强度)的共同影响。膝关节屈伸、展收活动的增大会导致膝关节负荷（内收力矩等）会增高。踇外翻足在前足内侧及大脚趾区有较大的峰值压强；鞋跟高度增加会导致足部负荷转移至前足内侧，压力中心线的内侧偏移也证实该结论。有限元模拟了健康足、轻度形变足及踇外翻足在正常站立、被动提踵及提踵旋转加载条件下的跖骨应力情况。不同鞋跟高度、运动强度和穿着习惯等研究发现对女性第一跖趾关节形变有重要科普教育性意义；对于临床和康复人员具有一定的理论指导意义。