Bound Gait

A running gait where a quadruped's two front legs land together, then the two rear legs land together, alternating front and back.

Bounding is a symmetric gait seen in quadruped animals and quadruped robots. The four legs are grouped into a front pair and a rear pair: both front legs touch down and lift off together, and likewise for the rear pair, with the two pairs alternating support and usually a flight phase — where the whole body leaves the ground — in between. A full cycle runs: front-leg stance, flight, rear-leg stance, flight. It's often compared alongside the diagonal trot (paired diagonal legs), the pace (paired same-side legs), and the pronk (all four legs synchronized); the body noticeably pitches up and down under this gait. Bounding suits high-speed running — MIT Cheetah 2 used it in high-speed experiments — and reinforcement-learning locomotion controllers often include it as one of several gaits selectable by command.

ExampleMIT Cheetah 2, in a 2017 IJRR paper, reached a top speed of 6.4 m/s using the bound gait in untethered 3D experiments; the Walk These Ways policy can switch among the trot, pronk, pace, and bound gaits on command.

Also called

Bounding, Bounding Gait

Related

Gait · Trot Gait · Pace Gait · Gallop Gait · Flight Phase (Aerial Phase) · Quadruped Robot

Sources

Yang & Bhounsule: Koopman Operator Based Linear MPC for 2D Quadruped Trotting, Bounding, and Gait Transition (arXiv 2507.14605)
Park, Wensing, Kim: High-speed bounding with the MIT Cheetah 2 (IJRR, 2017), MIT DSpace
Margolis & Agrawal: Walk These Ways (arXiv 2212.03238)