Spring-loaded inverted pendulum goes through two contraction-extension cycles during the single support phase of walking

摘要: Despite the overall complexity of legged locomotion, motion center mass (COM) itself is relatively simple, and can be qualitatively described by simple mechanical models. In particular, walking modeled a model in which each leg spring-loaded inverted pendulum (SLIP). However, SLIP has many limitations unlikely to serve as quantitative model. As first step obtaining for walking, we explored ability single-support phase found that two limitations. First, it predicts larger horizontal ground reaction forces (GRFs) than empirically observed. A new - angular radial (ARSLIP) overcome this deficit. Second, although spring (surprisingly) goes through contraction-extension-contraction-extensions (CECEs) during produce characteristic M-shaped vertical GRFs, modeling requires active elements. these limitations, provides important insights. It shows CECE cycling lengthens stance duration allowing COM travel passively longer, decreases velocity redirection between beginning end step.