Experimental Testing and Dynamic Simulation of Walking Gait for Transfemoral Prostheses

As prosthetic leg technology advances, accurate and efficientmethodsfor testing and evaluating prosthetic components are essential for further development. This work focused on developing a testing platform and performing a simulation model that can streamline prosthetic development and improve testing efficiency. Specifically, a gait simulator consisting of a six-degree-of-freedom (6-DOF) robotic arm integrated with a treadmill was developed to test transfemoral prostheses. The prostheses were fixed to the end of the robotic arm, which was controlled to track the trajectory and posture of the amputee’s residual thigh. In this case, the interactions between the residual limb and the prostheses were considered in this testing, as the motion of the residual limb has a great effect on the motion of the prostheses. Besides, the simulation model of the prostheses was developed to dynamically simulate the gait of the prostheses during walking. The parameters of the prostheses were tested by our platform. The gait of an above-knee amputee during walking was measured, and three prosthetic knees—Ottobock 3R80, Ottobock C-Leg, and a Liangkang Four-bar Linkage were tested here. Results show clear differences between amputee and healthy-subject thigh motion, highlighting the need for amputee-based testing. The gait simulator consistently achieved higher fidelity in reproducing knee kinematics, with average RMSE values of 4.06° vs. 5.64° (C-Leg), 4.70° vs. 8.40° (3R80), and 10.03° vs. 29.0° (Four-bar Linkage), along with higher correlation coefficients in all cases.