Shirota Camila, Simon Ann M, Rouse Elliott J, Kuiken Todd A
Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:7833-6. doi: 10.1109/IEMBS.2011.6091930.
In control subjects, trips during the early and late swing phase of walking elicit elevating and lowering strategies, respectively. However, the transition between these recovery strategies during mid-swing is unclear. A better understanding of this transition would provide insight into what factors cause individuals to choose one strategy over another. Three control subjects walked on a treadmill while attached to a custom-made tripping device. Perturbations of various lengths (ranging from 50 ms to 350 ms) were applied throughout the swing phase of gait. The results suggest that as perturbation length increased, the transition from elevating to lowering strategies occurred at earlier perturbation onsets. The transition period varied linearly with perturbation length. Perturbation lengths of 150 ms to 250 ms more closely replicated strategy selection in trips induced by real obstacles. Perturbations that are longer in duration force the transition from an elevating to a lowering strategy to occur at an earlier percentage of swing. These results show that perturbation length affects recovery strategy selection in response to trips.
在对照组受试者中，行走过程中早期和晚期摆动阶段的绊倒分别引发抬高和降低策略。然而，摆动中期这些恢复策略之间的过渡尚不清楚。更好地理解这种过渡将有助于深入了解哪些因素导致个体选择一种策略而非另一种策略。三名对照组受试者在连接到定制绊倒装置的情况下在跑步机上行走。在步态的整个摆动阶段施加了各种长度（范围从50毫秒到350毫秒）的扰动。结果表明，随着扰动长度增加，从抬高策略到降低策略的过渡发生在更早的扰动起始时刻。过渡期与扰动长度呈线性变化。150毫秒至250毫秒的扰动长度更接近真实障碍物诱发绊倒时的策略选择。持续时间更长的扰动迫使从抬高策略到降低策略的过渡在摆动的更早百分比时发生。这些结果表明，扰动长度会影响对绊倒做出反应时的恢复策略选择。
