背景:足结构的异常影响着足部的缓冲、动力及储能作用,研究表明足结构和足功能的生物力学评价方法对区分无症状的异常足型具有一定参考价值。目的:探究足结构及足功能的生物力学指标并对其进行分类梳理。方法:以"足结构,足功能&quo...背景:足结构的异常影响着足部的缓冲、动力及储能作用,研究表明足结构和足功能的生物力学评价方法对区分无症状的异常足型具有一定参考价值。目的:探究足结构及足功能的生物力学指标并对其进行分类梳理。方法:以"足结构,足功能""足底压力,压力中心轨迹""足弓,足横弓""步态""Foot function""Center of pressure""Flatfoot""Arch index"等关键词,在中国知网、百度学术、百链学术、PudMed、SpringeLink、Nature等数据库检索1993年1月至2020年5月有关文献,结合足的力学特性,从静态和动态两个方面,构建足结构的测试方法,探究足功能的生物力学评价手段。结果与结论:在静态形态学方面,用踝翻转指数和踝关节刚度评价了踝关节的结构和功能;用后跟小腿角和内侧纵弓角评价了后跟的结构和功能;以弓高指数和弓高适应性评价足弓的功能;用脚趾适应性评价拇指在外力矩下的功能;结合足姿指数的评分体系,系统地评价了足静态功能。在动态运动学方面,以行进间的足弓指数、压力中心曲线的特征及足翻转指数完成了动态足功能评价。展开更多
The majority of foot deformities are related to arch collapse or instability,especially the longitudinal arch.Although the relationship between the plantar fascia and arch height has been previously investigated,the s...The majority of foot deformities are related to arch collapse or instability,especially the longitudinal arch.Although the relationship between the plantar fascia and arch height has been previously investigated,the stress distribution remains unclear.The aim of this study was to explore the role of the plantar ligaments in foot arch biomechanics.We constructed a geometrical detailed three-dimensional (3-D) finite element (FE) model of the human foot and ankle from computer tomography images.The model comprised the majority of joints in the foot as well as bone segments,major ligaments,and plantar soft tissue.Release of the plantar fascia and other ligaments was simulated to evaluate the corresponding biomechanical effects on load distribution of the bony and ligamentous structures.These intrinsic ligaments of the foot arch were sectioned to simulate different pathologic situations of injury to the plantar ligaments,and to explore bone segment displacement and stress distribution.The validity of the 3-D FE model was verified by comparing results with experimentally measured data via the displacement and von Mise stress of each bone segment.Plantar fascia release decreased arch height,but did not cause total collapse of the foot arch.The longitudinal foot arch was lost when all the four major plantar ligaments were sectioned simultaneously.Plantar fascia release was compromised by increased strain applied to the plantar ligaments and intensified stress in the midfoot and metatarsal bones.Load redistribution among the centralized metatarsal bones and focal stress relief at the calcaneal insertion were predicted.The 3-D FE model indicated that plantar fascia release may provide relief of focal stress and associated heel pain.However,these operative procedures may pose a risk to arch stability and clinically may produce dorsolateral midfoot pain.The initial strategy for treating plantar fasciitis should be non-operative.展开更多
A good knowledge of midfoot biomechanics is important in understanding the biomechanics of the entire foot,but it has never been investigated thoroughly in the literature.This study carried out in vitro experiments an...A good knowledge of midfoot biomechanics is important in understanding the biomechanics of the entire foot,but it has never been investigated thoroughly in the literature.This study carried out in vitro experiments and finite element analysis to investigate the midfoot biomechanics.A foot-ankle finite element model simulating the mid-stance phase of the normal gait was developed and the model validated in in vitro experimental tests.Experiments used seven in vitro samples of fresh human cadavers.The simulation found that the first principal stress peaks of all midfoot bones occurred at the navicular bone and that the tensile force of the spring ligament was greater than that of any other ligament.The experiments showed that the longitudinal strain acting on the medial cuneiform bone was-26.2±10.8μ-strain,and the navicular strain was-240.0±169.1μ-strain along the longitudinal direction and 65.1±25.8μ-strain along the transverse direction.The anatomical position and the spring ligament both result in higher shear stress in the navicular bone.The load from the ankle joint to five branches of the forefoot is redistributed among the cuneiforms and cuboid bones.Further studies on the mechanism of loading redistribution will be helpful in understanding the biomechanics of the entire foot.展开更多
文摘背景:足结构的异常影响着足部的缓冲、动力及储能作用,研究表明足结构和足功能的生物力学评价方法对区分无症状的异常足型具有一定参考价值。目的:探究足结构及足功能的生物力学指标并对其进行分类梳理。方法:以"足结构,足功能""足底压力,压力中心轨迹""足弓,足横弓""步态""Foot function""Center of pressure""Flatfoot""Arch index"等关键词,在中国知网、百度学术、百链学术、PudMed、SpringeLink、Nature等数据库检索1993年1月至2020年5月有关文献,结合足的力学特性,从静态和动态两个方面,构建足结构的测试方法,探究足功能的生物力学评价手段。结果与结论:在静态形态学方面,用踝翻转指数和踝关节刚度评价了踝关节的结构和功能;用后跟小腿角和内侧纵弓角评价了后跟的结构和功能;以弓高指数和弓高适应性评价足弓的功能;用脚趾适应性评价拇指在外力矩下的功能;结合足姿指数的评分体系,系统地评价了足静态功能。在动态运动学方面,以行进间的足弓指数、压力中心曲线的特征及足翻转指数完成了动态足功能评价。
基金supported by the National Natural Science Foundation of China(Grant No. 30801163)
文摘The majority of foot deformities are related to arch collapse or instability,especially the longitudinal arch.Although the relationship between the plantar fascia and arch height has been previously investigated,the stress distribution remains unclear.The aim of this study was to explore the role of the plantar ligaments in foot arch biomechanics.We constructed a geometrical detailed three-dimensional (3-D) finite element (FE) model of the human foot and ankle from computer tomography images.The model comprised the majority of joints in the foot as well as bone segments,major ligaments,and plantar soft tissue.Release of the plantar fascia and other ligaments was simulated to evaluate the corresponding biomechanical effects on load distribution of the bony and ligamentous structures.These intrinsic ligaments of the foot arch were sectioned to simulate different pathologic situations of injury to the plantar ligaments,and to explore bone segment displacement and stress distribution.The validity of the 3-D FE model was verified by comparing results with experimentally measured data via the displacement and von Mise stress of each bone segment.Plantar fascia release decreased arch height,but did not cause total collapse of the foot arch.The longitudinal foot arch was lost when all the four major plantar ligaments were sectioned simultaneously.Plantar fascia release was compromised by increased strain applied to the plantar ligaments and intensified stress in the midfoot and metatarsal bones.Load redistribution among the centralized metatarsal bones and focal stress relief at the calcaneal insertion were predicted.The 3-D FE model indicated that plantar fascia release may provide relief of focal stress and associated heel pain.However,these operative procedures may pose a risk to arch stability and clinically may produce dorsolateral midfoot pain.The initial strategy for treating plantar fasciitis should be non-operative.
基金supported by the National Natural Science Foundation of China(11302154,11272273)China Postdoctoral Science Foundation(2013M530211)+1 种基金Opening Project of Shanghai Key Laboratory of Orthopaedic Implants(KFKT2013002)Fundamental Research Funds for the Central Universities
文摘A good knowledge of midfoot biomechanics is important in understanding the biomechanics of the entire foot,but it has never been investigated thoroughly in the literature.This study carried out in vitro experiments and finite element analysis to investigate the midfoot biomechanics.A foot-ankle finite element model simulating the mid-stance phase of the normal gait was developed and the model validated in in vitro experimental tests.Experiments used seven in vitro samples of fresh human cadavers.The simulation found that the first principal stress peaks of all midfoot bones occurred at the navicular bone and that the tensile force of the spring ligament was greater than that of any other ligament.The experiments showed that the longitudinal strain acting on the medial cuneiform bone was-26.2±10.8μ-strain,and the navicular strain was-240.0±169.1μ-strain along the longitudinal direction and 65.1±25.8μ-strain along the transverse direction.The anatomical position and the spring ligament both result in higher shear stress in the navicular bone.The load from the ankle joint to five branches of the forefoot is redistributed among the cuneiforms and cuboid bones.Further studies on the mechanism of loading redistribution will be helpful in understanding the biomechanics of the entire foot.
