Axial kinematics and muscle activity during terrestrial locomotion of the centipede Scolopendra heros
Axial kinematics and muscle activity during terrestrial locomotion of the centipede Scolopendra heros
复制标题
蜈蚣英雄陆地运动过程中的轴向运动学和肌肉活动
DOI：
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发表时间：
1995
影响因子：
2.8
通讯作者：
Jayne
中科院分区：
文献类型：
--
作者：
Anderson;Shultz;Jayne
对于以0.5、1.0和1.5倍体长每秒（L s⁻¹，其中L为体长）的速度在跑步机上稳定运动的蜈蚣，我们获得了运动的录像带，这些录像带与来自六个标准化纵向位置的侧屈肌的肌电图（EMGs）同步。对录像带逐场分析显示，在所有速度下都有向后传播的弯曲波。肌肉活动也以与运动波相同的速度向后传播，并且侧屈肌的肌电图通常是单侧的且交替的（在左右两侧之间）。肌电活动相对于侧向弯曲的时间与肌肉纤维缩短期间的电活动一致；因此，轴肌的活动似乎导致了侧向弯曲。方差分析表明，速度对运动学和肌电变量都有广泛的影响，而蜈蚣体内的纵向位置（在第8和第18体节之间）通常对相同变量没有显著影响。例如，当速度从0.5倍体长每秒增加到1.5倍体长每秒时，侧向位移的幅度大约翻倍，侧向弯曲的幅度大约增加三倍。表示运动学和肌电事件沿蜈蚣身体长度传播的滞后时间（以秒为单位）随速度显著降低。纵向部位之间的相位滞后随速度增加而显著降低，这表明运动学和肌电波长随速度增加而增加。肌电持续时间约为周期持续时间的50%，且不受速度影响，并且肌电活动相对于侧向弯曲的相位也不受运动速度影响。因此，所有速度下的所有结果都与蜈蚣运动过程中轴节的主动弯曲一致，这与被广泛接受的假说相矛盾，该假说认为侧向弯曲是由腿部的异步行进模式施加于身体的，并且弯曲受到轴肌的抵抗。
For centipedes moving steadily on a treadmill at speeds of 0.5, 1.0 and 1.5 L s-1, where L is body length, we obtained video tapes of movement that were synchronized with electromyograms (EMGs) from lateral flexor muscles at six standardized longitudinal positions. Field-by-field analysis of video tapes revealed posteriorly propagated waves of bending at all speeds. Muscle activity was also propagated posteriorly at the same speed as the kinematic wave, and EMGs of the lateral flexors were generally unilateral and alternating (between the left and right sides). The timing of EMG activity relative to lateral bending was consistent with electrical activity during the shortening of muscle fibers; therefore, activity of the axial musculature appears to cause lateral bending. Analysis of variance revealed widespread effects of speed on both kinematic and electromyographic variables, whereas longitudinal position within the centipede (between body segments 8 and 18) generally did not have significant effects on the same variables. For example, as speed increased from 0.5 to 1.5 L s-1, the amplitude of lateral displacement approximately doubled and the amplitude of lateral bending increased approximately threefold. Lag times (in seconds) indicating the propagation of kinematic and EMG events along the length of the centipede decreased significantly with speed. Phase lags among longitudinal sites decreased significantly with increased speed, indicating that the kinematic and EMG wavelengths increased with increased speed. EMG duration approximated 50 % of cycle duration and was unaffected by speed, and the phase of the EMG activity relative to lateral bending was also unaffected by locomotor speed. Hence, all results from all speeds are consistent with active bending of the axial segments during centipede locomotion, conflicting with the widely accepted hypothesis that lateral bending is imposed on the body by the metachronal stepping pattern of the legs and that bending is resisted by axial muscles.
DOI：
10.1242/jeb.152.1.453
发表时间：
1990
期刊：
The Journal of experimental biology
影响因子：
--
作者：
Carrier,D
通讯作者：
Carrier,D