Weir P L, MacKenzie C L, Marteniuk R G, Cargoe S L
Department of Kinesiology, University of Waterloo.
J Mot Behav. 1991 Sep;23(3):205-10. doi: 10.1080/00222895.1991.10118363.
The present experiment determined whether object texture influenced the transport and grasp components of human prehension. Infrared markers placed on the index finger, thumb, and wrist were recorded using a WATSMART system. The test objects were cylindrical dowels (103 mm high, 25 mm diameter, and 150 g in weight) of various surface materials (plain metal, coated with Vaseline, and covered with coarse sandpaper). Only temporal kinematic measures were affected by texture: Movement time (ms), time after peak deceleration (ms), percentages of movement time following maximum aperture, velocity, and deceleration were all significantly greater for the slippery dowel than the normal and rough dowels. Results indicated that the increased time associated with the slippery dowel could be explained entirely by increased time between contact with the dowel and dowel lift. Thus, these results are like those of Weir, MacKenzie, Marteniuk, Cargoe, and Frazer (1991), in which object weight was shown not to affect the free-motion phase, which includes the transport and grasp components of prehension. It appears that intrinsic object properties like weight and texture affect only the finger-object interaction phase of prehension; subsequent research is needed to dissociate inertial and surface friction effects while in contact with objects
本实验确定了物体质地是否会影响人类抓握动作中的运输和抓握部分。使用WATSMART系统记录放置在食指、拇指和手腕上的红外标记。测试物体是由各种表面材料（普通金属、涂有凡士林、覆盖粗砂纸）制成的圆柱形暗销（高103毫米，直径25毫米，重150克）。只有时间运动学测量受质地影响：对于光滑暗销，运动时间（毫秒）、峰值减速后的时间（毫秒）、最大孔径、速度和减速后的运动时间百分比均显著长于正常和粗糙暗销。结果表明，与光滑暗销相关的时间增加完全可以通过与暗销接触到暗销提起之间的时间增加来解释。因此，这些结果与威尔、麦肯齐、马滕纽克、卡戈和弗雷泽（1991年）的结果相似，在该研究中，物体重量被证明不会影响自由运动阶段，该阶段包括抓握动作的运输和抓握部分。看来物体的固有属性如重量和质地仅影响抓握动作的手指与物体相互作用阶段；需要后续研究来区分与物体接触时的惯性和表面摩擦效应。
