INTERLIMB COORDINATION DURING STEPPING IN THE CAT - IN-PHASE STEPPING AND GAIT TRANSITIONS
INTERLIMB COORDINATION DURING STEPPING IN THE CAT - IN-PHASE STEPPING AND GAIT TRANSITIONS
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DOI：
10.1016/0006-8993(82)90818-6
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发表时间：
1982-01-01
期刊：
影响因子：
2.9
通讯作者：
LENNARD, PR
中科院分区：
文献类型：
--
作者：
ENGLISH, AW;LENNARD, PR
在12只成年猫重复地上踏步试验中，研究了同相踏步和交替踏步过渡期间所有4个肢体之间的踏步周期协调性。不同肢体的步周期的时间间隔从每个肢体的单个伸肌的肌电图（EMG）活动的分析中确定。模式的协调不同的肢体的基础上的频率与分离步骤周期遇到的相位值。其中两个后肢的步周期的相位比真正的交替更接近于真正的同相协调的步（相位在270 °和90 °之间），并且在前面和后面的步骤中发现类似偶联的情况被定义为稳态条件。在稳定条件下，注意到前肢-前肢和前肢-后肢步进循环的不同协调模式。在步进序列，包括过渡到或从交替步进，渐进和突然的相位变化被发现。在前肢前肢和前肢后肢相位关系的变化往往是渐进的比突然的。在一个这样的分支对之间的相位关系的变化中遇到突然变化的情况下，另一对中的相位变化是渐进的。后肢-后肢相位关系的变化几乎总是突然的。4个肢体在同相步进期间根据一些模式进行协调，但是这些模式的可变性使得它们与简单的神经回路的关联相当投机。过渡是最常见的渐进的发现是解释的interlimb控制的状态依赖模型，其中使用的过渡类型取决于所有4肢的步骤周期的神经耦合的强度在过渡开始的时候。
The coordination of step cycles between all 4 limbs during in-phase stepping and during transitions to and from alternate stepping was studied in 12 adult cats during repeated overground stepping trials. The temporal spacing of step cycles of the different limbs was determined from analysis of electromyographic (EMG) activity in a single extensor muscle of each limb. Patterns of coordination of the different limbs were established on the basis of the frequency with which phase values separating step cycles were encountered. Steps in which the phasing of step cycles of the 2 hindlimbs were closer to true in-phase coordination than true alternation (phase between 270 and 90.degree.), and where similar coupling was found in both the preceding and following steps were defined as steady state conditions. Distinct patterns of coordination of forelimb-forelimb anfd forelimb-hindlimb step cycles were noted under steady conditions. During stepping sequences which include transitions either to or from alternate stepping, both gradual and abrupt phase changes were found. The changes in both forelimb-forelimb and forelimb-hindlimb phase relationships were more often gradual than abrupt. Where abrupt changes were encountered in the change in phase relationships between 1 such limb pair the phase change in the other pair was gradual. Changes in hindlimb-hindlimb phase relationships phase relationships during transitions were nearly always abrupt. The 4 limbs are coordinated during in-phase stepping according to a few patterns, but that the variability about these patterns makes their association with simple neural circuitry rather speculative. The finding that transitions were most often gradual is interpreted in terms of a state-dependent model of interlimb control, in which the type of transition utilized depends on the strength of neural coupling of step cycles of all 4 limbs at the time that the transition is initiated.