Optimization of Torsional Spring Constants for Walking Assist Devices Using Torsion Springs Based on Dynamics Simulation

Abstract

In this study, we conducted musculoskeletal simulations to optimize the spring of a walking assist device using a torsion spring, and performed comparative experiments with a device using a spring of different strength. Muscle activity during walking and lower limb joint angles were measured in the experiments. Simulation results for changing the spring of the walking assist device showed that a spring stiffness of 50 N・mm/deg is optimal. The results of the comparative experiments with and without the walking aids showed improved muscle activity in all measured muscles for two subjects, including the participant who provided motion data during the simulation and another individual. Furthermore, wearing the assist device led to distinct variations in joint angles for each individual participant. Additionally, through a comparison of the participants' physical characteristics, it became evident that factors such as leg and foot length significantly influenced the performance of the device.