Design of motion trajectory and external force on foot based on musculo-skeletal model in robot-assisted lower limb rehabilitation

Abstract

Many methods for physical medicine and rehabilitation strategies have been developed for physically disabled people. Most of them have been determined by physical therapists based on anatomical and physiological assessment of the subject. With application of robot technology which allows smooth achievement of complex trajectories, and with loading or assisting designated muscles in an accurate manner, a better rehabilitation strategy can be developed. In this paper, we propose a new method to design the motion trajectory of lower limbs and the applied forces acting on the foot. In order to improve the rehabilitation effect in full consideration of biomechanical stability of the trajectory and musculo-skeletal model of each subject, we have applied genetic algorithm to search the parameters of spline curves for the trajectory and the applied force acting on subject's foot. The usefulness of the proposed method is confirmed through simulation results and the comparison with a conventional training trajectory. © 2011 The Japan Society of Mechanical Engineers.