Automating the lower limb gait cycle for transfemoral amputee prosthetics

Abstract

This study presents the development of a powered transfemoral prosthetic leg designed to automate and replicate the human lower limb gait cycle. The study has also addressed the limitations of current passive and myoelectric prosthetics such as limited adaptability, high energy consumption, and poor terrain response. This project focuses on capturing gait patterns through motion analysis and integrating those into a bio-inspired and mechanically actuated limb. The motion captured data from healthy subjects informed the control algorithms and mechanical joint behavior by ensuring phase-accurate replication of swing and stance motions. The system features a planetary gear-driven knee and ankle, supported by real-time sensor input and a PID based control structure to ensure synchronized and adaptive motion. A key feature of the prototype is adaptive balance through compensatory responses. The prototype was validated through comparative gait analysis, which confirms that joint angle trajectories and timing closely mimic natural human movement. By emphasizing user mobility and safety, structural efficiency, and motion fidelity, this work contributes to the advancement of assistive prosthetic technologies, particularly for transfemoral amputees seeking greater independence and enhanced biomechanical compatibility.