Dynamics of lateral undulation in legged terrestrial locomotion*

Although undulatory locomotion is commonly associated with limb-less animals such as snakes, there exist instances of slender multi-legged animals where undulation is also observed. In centipedes, for example, lateral body undulations emerge when they move fast, although the causes for the appearance of undulations have not been unequivocally clarified. A key unresolved question is whether undulation in myriapod locomotion arises due to the natural dynamics of the organism or if it is neurally enforced. To answer this question, we developed and studied a dynamical model that accounts for biologically plausible leg kinematics and morphologies. The insights obtained from the model analysis will be presented together with their implications for the evolution of locomotor morphology in many-limbed organisms, the principles of propulsion in terrestrial locomotion, and the design of robotic locomotion systems.