The advantages of a rolling foot in human walking

摘要: The plantigrade human foot rolls over the ground during each walking step, roughly analogous to a wheel. center of pressure progresses on like wheel radius 0.3 L (leg length). We examined effect varying curvature mechanics and energetics walking. controlled by attaching rigid arc shapes various radii bottoms boots restricting ankle motion. measured mechanical work performed mass (COM), net metabolic rate, in subjects (N=10) with seven from 0.02-0.40 m. Simple models dynamic predict that redirection COM velocity requires step-to-step transition work, decreasing quadratically radius. Metabolic cost would be expected change proportion work. average rate negative COM, found it followed trend well (r2=0.95), 2.37 times as much for small large. Net (subtracting quiet standing) also decreased increasing minimum at L, slight increase thereafter. Maximum was 6.25 W kg(-1) (for small-radius feet), about 59% greater than 3.93 kg(-1), which turn 45% normal fit reasonably (r2=0.86) quadratic curve, but exceeded extreme sizes. Other factors appear very large feet. These may include effort expended stabilize joints (especially knee) or maintain balance. Rolling feet energetically advantageous walking, partially due transitions.