Meeting Abstract

25.5  Saturday, Jan. 4 14:30  Why the trot? REVZEN, S*; BURDEN, S/A; KVALHEIM, M/D; University of Michigan; University of California, Berkeley; University of Michigan

The trot and pace gaits of quadrupeds and the alternating tripod gait of running hexapods are just the most familiar of the many multiple contact gaits that multilegged animals utilize. We define “multiple contact gaits” to be those in which multiple legs touch down with near simultaneity. Arguments of collision angle suggest that such gaits are inherently less energetically efficient than rotary gallops and metachronal gaits. We present new results from dynamical systems theory which suggest that multiple contact gaits benefit from a unique, hitherto unknown, form of stability which makes them particularly robust to uncertainties in muscle actuation and ground traction. We conjecture that this advantage, conferred by the inherent the structure of the mechanical dynamics, accounts at least in part for the convergent appearance of multiple contact gaits across virtually all terrestrial animal taxa.