Comparison of nonlinear lower limb joint variability using imu and motion capture based kinematics

The aim of this study is to compare an IMU-based system with a motion capture system in relation to nonlinear analysis of kinematics. Subjects were asked to walk on an instrumented treadmill at their self-selected walking speed and the Lyapunov exponent, a measure of stride-to-stride variability, was calculated for ankle and knee flexion for each system. A significant relationship between systems was observed for LyE at the knee, but not the ankle. Peak flexion angles for the ankle and knee were significantly related between systems.