Timmann D, Stelmach G E, Bloedel J R
Department of Exercise Science, Arizona State University, Tempe 85287, USA.
Exp Brain Res. 1996 Mar;108(3):486-92. doi: 10.1007/BF00227271.
The kinematic changes associated with the manipulation and transport components during a prehensile movement were examined using an experimental paradigm that required alterations in only the manipulation component. Instead of starting with the thumb and index finger naturally together (control condition), subjects began the reach-to-grasp movement with their thumb and fingers fully extended (experimental condition). In contrast to the control condition, in the experimental conditions the thumb and index finger started to close during wrist transport, then opened again prior to object grasp. In addition, there was a brief inflection in the ascending portion of the velocity profile of the wrist in over half the trials. However, all the primary features of the transport component profile remained unaltered. The results suggest that there can be substantial reorganization of the grip aperture during the first part of the reach without altering the temporal and spatial relationships between grip aperture and transport as the object to be grasped is approached.
使用一种实验范式来检查在抓握动作期间与操作和运输部分相关的运动学变化，该范式仅要求改变操作部分。受试者不是从拇指和食指自然并拢开始（对照条件），而是在伸手抓握动作开始时将拇指和手指完全伸展（实验条件）。与对照条件相比，在实验条件下，拇指和食指在手腕运输过程中开始闭合，然后在抓握物体之前再次张开。此外，超过一半的试验中，手腕速度曲线上升部分出现了短暂的拐点。然而，运输部分曲线的所有主要特征保持不变。结果表明，在伸手的第一部分，抓握孔径可能会有实质性的重新组织，而在接近要抓握的物体时，不会改变抓握孔径与运输之间的时间和空间关系。
