The effects of gait strategy on metabolic rate and indicators of stability during downhill walking

摘要: When walking at a given speed, humans often appear to prefer gait patterns that minimize metabolic rate, thereby maximizing economy. However, recent experiments have demonstrated do not maximize economy when downhill. The purpose of this study was investigate whether non-metabolically optimal behavior is the result trade-off between and stability. We hypothesized ability modulate their strategy increase either or stability, but in one measure will be accompanied by decrease other. Subjects walked downhill using strategies ranging from risky conservative, which were prescribed verbal instructions induced threat perturbations. quantified spatiotemporal characteristics, rate several indicators stability previously associated with fall risk: stride period variability; step width Lyapunov exponents; Floquet multipliers; fractal index. subjects conservative strategies, periods lengths decreased, increased, anteroposterior maximum exponents has been interpreted as an indicator decreased These results provide clear support for proposed particularly approximated complex metrics. pattern changes linked increased risk observed our healthy strategy, suggesting these may response to, rather than cause of, risk.