Derivation and Simulation of the External Force Waveform for Pelvic Support Control in Walker-Assisted Gait

Abstract

  This study investigates the mechanical effects of therapeutic assistance on pelvic control in walker-assisted gait. Specifically, it examines how external forces and moments applied to the pelvis by a physical therapist influence overall gait dynamics. Four healthy adults participated in the study, each using a walker with their right lower limb load restricted to 70% of body weight to simulate a rehabilitation scenario. During this exercise, the assistance forces and torques provided by a physical therapist were measured, revealing a periodic pattern aligned with the gait cycle. Using MATLAB Simulink, these recorded assistance patterns were applied in a simulation environment to replicate the swing phase, allowing researchers to systematically assess the effects of external forces and moments on lower limb and pelvic motion. Results indicated that these periodic assistance force patterns significantly influenced pelvic rotation and tilt, thereby affecting stride length and swing motion. These findings suggest that controlled, periodic pelvic support can stabilize gait, supporting a more natural walking pattern even under load restrictions. The study points to potential applications in robotic assistive devices, which could incorporate controlled, periodic external forces to mimic therapeutic intervention, offering enhanced gait stability and supporting rehabilitation objectives.