Compass-Gait Walker: Inverted-Pendulum Gait Dynamics

Human walking is often reduced, for analysis, to the "compass gait": two straight rigid legs and a point mass at the hip, swinging as an inverted pendulum during single-leg stance and colliding with the ground at every heel-strike. This simulator runs that real biomechanical model in 3D — the stance leg falls forward under gravity exactly as θ'' = (g/L)sinθ dictates, each heel-strike applies the standard rigid-leg collision that scrubs off velocity as ω⁺ = ω⁻cos(2α), and a tunable push-off impulse (standing in for ankle plantarflexion or a powered prosthetic ankle) replaces the lost energy so the gait can settle into a stable, repeating cycle instead of stumbling to a halt. Live readouts track walking speed, cadence, step length and vertical ground-reaction force exactly as a force-plate would report them in a gait-rehabilitation lab, making this the same passive-dynamics-plus-push-off model used to study energy-efficient walking, exoskeleton control and prosthetic-ankle push-off tuning.