The Research Of Movement Biomechanical Characteristics And Rehabilitation Applications Of Human Lower Limb

Walking is the most basic and important activity in human daily life.It will show a variety of gait when the lower limbs appear dyskinesia.The study of gait characteristics provides an effective basis for understanding the regularity of human movement and designing rehabilitation devices.In this paper,by analyzing the physiological structure of the lower limb joints,the motion mechanics data of them were obtained by using motion capture device,medical force plate and human movement biomechanical simulation system.The mathematical models describing the gait characteristics were established.Then,a rehabilitation evaluation system based on gait shape parameters and lower limb torques was proposed.The finite element model of knee joint was established and the biomechanical changes of each tissue at typical moments of gait cycle were analyzed.Finally,the multi-attribute topology graph was proposed to design and analyze the structure of rehabilitation training mechanism.The main research work and achievements of this paper are as follows:(1)An experimental method was presented to acquire gait data of lower limb joints by motion capture system and medical force plate.After the data correction from VICON Nexus and Mokka softwares,the displacements,angles,ground reaction forces,resultant forces and resultant moments of joints were simulated by human movement biomechanical simulation system.(2)The similarity between parameter curve and gait curve was analyzed and compared.Based on GE-Bézier curv e,the gait mathematical models with common control points and shape parameters were constructed to describe the displacement and angle data of the three joints in the sagittal plane.The ranges of the shape parameters in normal group were summarized as the reference standards for judging whether the gait is abnormal or not.(3)According to the influence of gait and posture on shape parameters,and the correlation between the torque exerted by lower limbs and the degree of rehabilitation,a rehabilitation evaluation system including the parameters of joint displacement,angle,and torque was proposed.(4)The finite element model of the knee joint was established.Through the analysis of gait parameters,seven typical moments of gait cycle were selected for finite element simulation.Thus,the stress and displacement changes of each tissue of the knee joint during normal walking were obtained.At the same time,the biomechanical characteristics of knee joint at two typical moments were analyzed when using rehabilitation institution for lower limb training.(5)Based on the shape characteristics of displacement trajectories of normal gait and the movement modes of patients with lower limb injury,the functional requirements of lower limb rehabilitation training mechanism were summarized.A multi-attribute topological graph describing the structure and state characteristics of gear trains was put forward to design and analyze the rehabilitation mechanism.Finally,the lower limb rehabilitation training mechanism with planetary gear train as the main body and sliding gears for active and passive mode conversion was determined.The research results of this paper comprehensively revealed the movement and force regularities of lower limb joints during human walking.They not only have theoretical guiding significance and practical value for evaluating the effect of lower limb rehabilitation training,but also provides references for the design of lower limb rehabilitation training device.