An EMG-driven musculoskeletal model of the human lower limb for the estimation of muscle forces and moments at the hip, knee and ankle joints in vivo

This work presents the design of a novel neuromusculoskeletal model (NMS) of the human lower limb to estimate muscle forces and moments about the hip, knee and ankle joints. This research shows it is possible to use electromyographic (EMG) signals recorded from 16 muscles to drive 34 musculotendon actuators and constrain their operation to simultaneously satisfy the production of moments across several degrees of freedom (DOF) including: hip adduction-abduction, hip flexion- extension, knee flexion-extension, ankle dorsi-plantar flexion. Past research proposed the use single-DOF NMS model to estimate muscle forces and joint moments. However, these models do not properly allow muscles to operate with respect to all the DOFs associated to the joints they span. This leads to unrealistic estimations of muscle activation patterns and force production dynamics. Our proposed model was able to generate muscle forces that properly satisfied the moments generated at hip, knee and ankle joints during a variety of dynamic motor tasks.