STUMBLING REACTIONS IN MAN - SIGNIFICANCE OF PROPRIOCEPTIVE AND PRE-PROGRAMMED MECHANISMS
STUMBLING REACTIONS IN MAN - SIGNIFICANCE OF PROPRIOCEPTIVE AND PRE-PROGRAMMED MECHANISMS
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DOI：
10.1113/jphysiol.1987.sp016527
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发表时间：
1987-05-01
影响因子：
5.5
通讯作者：
SILLEM, M
中科院分区：
文献类型：
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作者：
DIETZ, V;QUINTERN, J;SILLEM, M
1. 在跑步机上行走时，腿部肌肉组织的肌电图反应和相应的关节运动被研究，这是由随机定时的跑步机加速脉冲产生的，其振幅和加速速度可预测或不可预测。2. 扰动后同侧腓肠肌肌电反应的上升速率取决于跑步机加速的速率。对于给定的加速度，肌电反应的振幅和峰值的时间取决于脉冲的振幅，而腓肠肌反应的上升速度对于小振幅和大振幅的脉冲都是相同的。高加速时，起始潜伏期较短（65 ms），低加速时，起始潜伏期较长（85 ms）。3. 同侧股二头肌反应的振幅远小于腓肠肌反应，但在不可预测的脉冲下比可预测的脉冲大。4. 最初腓肠肌反应后，胫前肌激活伴腓肠肌凹陷，有时伴有第二次腓肠肌弱激活。腓肠肌凹陷在相对于反应开始的固定时间范围内结束。胫骨前肌的激活在高加速度但振幅小的不可预测的脉冲诱发时最为明显。5. 由此可见，腓肠肌第一反应的产生明显受到肌肉本体感觉信息的持续控制，可以用拉伸反射反应来最好地描述。根据二相或三相脑电图模式的证据表明，为了产生适当的脑电图模式，中枢程序和肌肉本体感觉输入之间发生了密切的相互作用。6. 根据早期的工作（Berger， Dietz和Quintern， 1984a）和目前的结果，我们认为肌电反应可能主要是由第二组传入的肌肉本体感觉输入介导的。这种输入由与脊髓运动中枢紧密相连的脊髓神经元间回路调节和处理。处理方式取决于各种因素，例如脉冲性质的可预测性。
1. Electromyogram (e.m.g.) responses of the leg musculature and the corresponding joint movements were studied following a perturbation of the limb during walking on a treadmill, produced by a randomly timed treadmill acceleration impulse, either predictable, or unpredictable in its amplitude and rate of acceleration. 2. The rate of rise of ipsilateral gastrocnemius e.m.g. response following a perturbation was dependent on the rate of treadmill acceleration. For a given acceleration rate the amplitude of the e.m.g. response and the timing of its peak was dependent on the amplitude of the impulse and the rate of rise of the gastrocnemius response was the same for impulses of both small and large amplitude. The onset latency was shorter (65 ms) for high accelerations and longer (85 ms) for lower ones. 3. The amplitude of the ipsilateral biceps femoris response was much smaller than the gastrocnemius response but was larger following unpredictable than predictable impulses. 4. The initial gastrocnemius response was followed by a tibialis anterior activation associated with a gastrocnemius depression and sometimes with a second, weak gastrocnemius activation. The gastrocnemius depression ended within a fixed time range relative to the onset of the response. The tibialis anterior activation was most pronounced when unpredictable impulses with high acceleration but a small amplitude were induced. 5. It is concluded that generation of the first gastrocnemius response is obviously under continuous control by muscle proprioceptive information and can be best described in terms of a stretch reflex response. It is suggested that, on the evidence of the diphasic or triphasic e.m.g. pattern, a close interaction occurs between a central programme and muscle proprioceptive input in order to generate the appropriate e.m.g. pattern. 6. On the basis of earlier work (Berger, Dietz and Quintern, 1984a) and on the present results it is suggested that the e.m.g. responses may be mediated mainly by muscle proprioceptive input from group II afferents. This input is modulated and processed by spinal interneuronal circuits, closely connected with spinal locomotor centers. The mode of processing depends on various factors, such as the predictability of the nature of the impulse.