Three-Dimensional Finite Element Modeling Of Foot And Its Mechanical Response Analysis To Load And Posture Changes

The foot is an endmost human organ in direct contact with the ground,which can support body weight,balance force,and mitigate shock.The foot biomechanics study could provide foot care during exercise and the comfortable design of footwear with technical support.This thesis studies the foot biomechanical property responses to different body loads and landing postures based on the 3D reconstruction of the foot and the foot musculoskeletal system.The major work and innovative points of the thesis are as follows:The research status of the foot biomechanics and the finite element analysis of the foot are introduced.The key and difficult points,as well as the research and application trends,are expounded.The main research content,and the framework of the paper are given.The anatomic structures of the foot and ankle are analyzed.The foot images of participants are obtained using the CT(computed tomography)plain scan.Based on the captured images,the point cloud data of foot bones and muscles is generated using Mimics software.Moreover,the point cloud data is processed and optimized by the software Geomagic.Thus,a smooth geometric model of the foot is obtained.The 3D geometric model of the foot constructed using reverse engineering technology is pre-processed using the software Hypermesh.The processing of the foot geometric model and the setting of the contact relationship are conducted according to the foot anatomical characteristics.Then,the finite element model of the foot musculoskeletal system is built based on the foot parts' metrical constitutive model.Furthermore,the finite element model is validated by a barefoot standing plantar pressure measurement test.The foot biomechanical property responses to different body loads are studied based on the finite element model of the foot musculoskeletal system.The human body loads are reasonably designed and set in the finite element model.Trends and characteristics of distribution of plantar pressure,tissue stress and tissue displacement are analyzed for the body loads under 0.5,1,and 2 times body weight when the human stand in balance with two feet.Similarly,the impacts of the landing posture on the foot biomechanical property are studied based on the foot musculoskeletal system's finite element model.The biomechanical simulation analysis of the foot for the landing postures of forefoot-first,neutral posture,and heel-first.The stress levels in the metatarsal region,the stress of calcaneus,and the tension of plantar fascia are analyzed for different landing postures.Finally,the thesis is summarized,and future research is outlined.