Research On Lower Limb Movement Differences Of Human Ground-walking And Treadmill-walking

With the development of science and technology and requirements of people to improve the quality of life,sports biomechanics plays an increasingly important role in fields such as sports,medical treatment,ergonomics,gait recognition,aerospace.The study of gait is one of the key researches in biomechanics both now and the future,however,most of the gait information is accomplished and got by means of a treadmill platform,the differences of motion in the ground and treadmill is ignored.The commonness and differences in biomechanical characteristics of lower extremity joint when walking on a treadmill and the ground are studied in this paper as follows:First,a three degrees of freedom theoretical model of the lower extremities in sagittal plane is established basing on the Lagrange equations,and then Euler equations is combined to derived joint reaction force and torque analytical expressions for hip,knee and ankle jointe when the joint friction is considered.A wireless of gait phase information detection system combines FAB system is designed and so do the hardware circuitry and software.After the design of measurement experiment and completion of measuring gait kinematics and some kinetic parameters.In order to get ideal experimental data,mathematical treatment is carried on the experimental data by interpolation,Pauta criteria and function model coefficient correction method.Secondly,the lower limb biomechanics semi-physical simulation platform which uses kinematic data measured experimentally as input is set up with SimMechanics.Theoretical calculations of lower extremity dynamics and model data acquisition based on SimMechanics are accomplished with the use of the experimental data of lower limb joints corner as known quantities,by comparing the experimental kinetic data with the model kinetic data of lower extremity,the correctness of theoretical models and simulation models are verified,and then the characteristics for lower extremity joint reaction force,joint torque are described.Finally,commonness and differences in kinetic parameters of various lower limb joints are researched when walking on a treadmill and the ground,the causes of the differences is analyzed.Established mathematics model for the lower limb angle with hip,knee and ankle joint on the base of the Gauss function,the Fourier function and Sin function,for the characteristics of walking on a treadmill,the gait phase difference while walking on the ground and on a treadmill is explored,and the impact of the differences for gait is analyzed.