The dynamics of gait transitions: Effects of grade and load
The dynamics of gait transitions: Effects of grade and load
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DOI：
10.1080/00222899809601323
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发表时间：
1998-03-01
影响因子：
1.4
通讯作者：
Warren, WH
中科院分区：
文献类型：
--
作者：
Diedrich, FJ;Warren, WH
Diedrich和Warren(1995A)提出步态转换类似于吸引子之间的分叉，以腿段的相对相位为序参数，以步频和步长为控制参数。在目前的实验中，作者测试了这样一种预测，即操纵吸引器布局，无论是通过增加脚踝的负荷还是通过增加跑步机的等级，都会在步行-跑步转变中诱导相应的变化。正如预测的那样，负荷操作转移了最稳定的行走和向较低的步频过渡。相比之下，坡度操作改变了最稳定的行走和过渡到更短的步长。动力学理论的其他特征也被复制，包括相位的增强波动以及过渡时步长和频率的系统性变化。总体而言，在这些实验中，控制参数空间中吸引子的移动会产生相应的转换移动。
Diedrich and Warren (1995a) proposed that gait transitions behave like bifurcations between attractors, with the relative phase of the leg segments as an order parameter and stride frequency and stride length as control parameters. In the present experiments, the authors tested the prediction that manipulation of the attractor layout, either through the addition of load to the ankles or through an increase in the grade of the treadmill, induces corresponding changes in the walk-run transition. As predicted, the load manipulation shifted the most stable walk and the transition to lower stride frequencies. In contrast, the grade manipulation shifted the most stable walk and the transition to shorter stride lengths. Other features of the dynamic theory were also replicated, including enhanced fluctuations of phase and systematic changes in stride length and frequency at the transition. Overall, in these experiments a shift of the attractors in control parameter space yielded a corresponding shift of the transition.