Residual Elimination Algorithm Enhancements to Improve Foot Motion Tracking During Forward Dynamic Simulation of Gait

During inverse dynamic simulations of human movement, inaccuracies and noise in experimental data result in residual forces and torques acting on the pelvis [1]. These quantities are physically unrealistic but are necessary to balance the equations of motion. To circumvent this problem, Remy and Thelen developed a residual elimination algorithm (REA) that employs forward dynamic simulation to produce dynamically consistent accelerations that best agree with experimental marker motion data and satisfy the whole-body equations of motion [2]. While the kinematics are dynamically consistent and the pelvis residuals effectively eliminated, the inability of REA to reproduce foot marker motion accurately is a hindrance for applications requiring precise positioning of the feet (e.g., foot-ground contact models).