Bimechanical Study Of Lower Limb Muscloskeletal Motion System Based On OpenSim

It is the foundation for the body’s postural changes to move lower limb when moving.In recent years,lower extremity motor dysfunction has become a highly popular disease,and the demand for helping the enhancement of human locomotion is increasing,and the study of biomechanical properties of the lower extremity is becoming more and more important.Traditional rigid models cannot represent the joint motion,joint forces and muscle metabolism,and at this stage,the construction of musculoskeletal systems based on simulation technology has become the basis for biomechanical research.In this paper,it is important to focus on the lower extremity motion and conduct a study related to the modeling and simulation of musculoskeletal movement system based on computer technology.The 3D dynamic capture technology is used to reproduce different postural movements of the human body,and the level of muscle activation and metabolism was obtained with the help of OpenSim platform dynamics simulation to simulate the motion performance of the system under the action of assistive devices.The specific research includes:(1)The motion mechanism of human musculoskeletal system and construct a musculoskeletal model of the lower limbs based on the OpenSim platform was conducted to study.(1)The mechanism of the human musculoskeletal system and construct a musculoskeletal model of the lower extremity based on OpenSim platform was conducted to learn.The ankle joint torque spring coupling model based on human-machine modeling method was conducted to create.A single muscle-driven bouncing model and design an interactive interface to realize the comparison of muscle activation output under different assist strategies was conducted to construst,and the effectiveness of the assist strategies by comparing the activation degrees was conducted to verify.(2)3D motion capture experiment was carried out.Select a motion capture system and build an experimental site to collect human motion and ground reaction forces under normal gait,side kick,and squat states.Marker points were configured according to the experimental requirements,and data recognition,coordinate transformation and format conversion were completed.The kinematic data and ground reaction data are loaded well to realize the motion reproduction of the three conditions,and to complete the gait prediction simulation,ankle joint stability simulation and squat prediction simulation with the collected kinematic data.(3)The motion simulation of the lower limb musculoskeletal movement system based on the OpenSim platform was conducted to realize.The inverse kinematic and inverse kinetic calculations are performed on the basis of the scaled model to obtain the net joint moments,and the residual reduction is used to minimize the compensating forces arising from the stacking of model and marker data errors during the solution calculation.The change in activation of the right leg gastrocnemius before and after actuator addition was compared using static optimization,demonstrating that the additional torque generated when the actuator is involved in gait motion reduces the activation of the gait muscle group.Muscle calculation controls were obtained for the metabolic levels of the muscle groups without the addition of the ankle torque spring and with different stiffnesses of the torque spring.The results show that the overall metabolic level of the musculoskeletal model under the action of the exoskeletal assistive device is reduced by 20%-30% compared to the original state,completing the process design for simulating the effectiveness of the assistive device assistance and realizing the joint feedback and muscle evaluation during the assistance process.