Posturally induced transitions in rhythmic multijoint limb movements.
Posturally induced transitions in rhythmic multijoint limb movements.
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姿势诱导有节奏的多关节肢体运动的转变。
DOI：
10.1007/bf00230476
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发表时间：
1993
影响因子：
2
通讯作者：
Kelso,JA
中科院分区：
文献类型：
--
作者：
Buchanan,JJ;Kelso,JA
协调动态（例如，稳定性，失去稳定性，切换）的多关节手臂运动的前臂旋转的函数进行了研究。在下列条件下检查右肘和右腕屈伸的节律协调性：（1）前臂仰卧（前臂角度0°），同时协调腕屈/肘屈和腕伸/肘伸（称为同相）;前臂俯卧（前臂角度160°），同时协调腕关节屈曲/肘关节伸展和腕关节伸展/肘关节屈曲（称为反相）。在任一模式中，受试者以9个20°的步骤旋转前臂，以1.25 Hz的频率每步产生15个运动周期。在一个关键的前臂角度，观察到从模式1到模式2和从模式2到模式1的自发转换。临界角取决于前臂旋转变化的方向，从而揭示了开关过程的滞后性。在过渡的途中，无论前臂旋转的方向如何，在关节之间的相对定相中观察到相位波动的增强和扰动响应时间的增加（临界减慢）。这种观察支持失去稳定性作为一个中央，自组织过程的基础协调变化。支持多关节协调动力学的神经生理机制进行了讨论。
The coordination dynamics (e.g., stability, loss of stability, switching) of multijoint arm movements are studied as a function of forearm rotation. Rhythmical coordination of flexion and extension of the right elbow and wrist was examined under the following conditions: (1) forearm supine (forearm angle 0°), simultaneous coordination of wrist flexion/elbow flexion and wrist extension/elbow extension (termed in-phase); and (2) forearm prone (forearm angle 160°), simultaneous coordination of wrist flexion/elbow extension and wrist extension/elbow flexion (termed anti-phase). Starting in either pattern, subjects rotated the forearm in nine 20° steps, producing 15 cycles of motion per step at a frequency of 1.25 Hz. Spontaneous transitions from pattern 1 to pattern 2 and from pattern 2 to pattern 1 were observed at a critical forearm angle. The critical angle depended on thedirectionof forearm rotational change, thus revealing thehystereticnature of the switching process. En route to the transition, regardless of direction of forearm rotation,enhancement of phase fluctuationsand an increase in perturbation response times (critical slowing down) were observed in the relative phasing between the joints. Such observations support loss of stability as a central, self-organizing process underlying coordinative change. Neurophysiological mechanisms supporting multijoint coordinative dynamics are discussed.