A muscle-reflex model that encodes principles of legged mechanics produces human walking dynamics and muscle activities

Abstract

While neuroscientists identify increasingly complex
neural circuits that control animal and human gait, biomechanists
find that locomotion requires little control if principles of legged
mechanics are heeded that shape and exploit the dynamics of
legged systems. Here we show that muscle reflexes could be
vital to link these two observations. We develop a model of
human locomotion that is controlled by muscle reflexes which
encode principles of legged mechanics. Equipped with this reflex
control, we find this model to stabilize into a walking gait from
its dynamic interplay with the ground, reproduce human walking
dynamics and leg kinematics, tolerate ground disturbances, and
adapt to slopes without parameter interventions. In addition,
we find this model to predict some individual muscle activation
patterns known from walking experiments. The results suggest
not only that the interplay between mechanics and motor control
is essential to human locomotion, but also that human motor
output could for some muscles be dominated by neural circuits
that encode principles of legged mechanics.