Massey J T, Lurito J T, Pellizzer G, Georgopoulos A P
Philip Bard Laboratories of Neurophysiology, Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD 21205.
Exp Brain Res. 1992;88(3):685-90. doi: 10.1007/BF00228198.
Normal human subjects grasped a 3-D isometric handle with an otherwise unrestrained, pronated hand and exerted forces continuously to draw circles, ellipses and lemniscates (figure-eights) in specified planes in the presence or absence of a 3-D visual force-feedback cursor and a visual template. Under any of these conditions and in all subjects, a significant positive correlation was observed between the instantaneous curvature and angular velocity, and between the instantaneous radius of curvature and tangential velocity; that is, when the force trajectory was most curved, the tangential velocity was lowest. This finding is similar to that obtained by Viviani and Terzuolo (1982) for 2-D drawing arm movements and supports the notion that central constraints give rise to the relation between geometric and kinematic parameters of the trajectory.
正常人类受试者用一只处于旋前位且无其他限制的手握住一个三维等距手柄，并在有或没有三维视觉力反馈光标和视觉模板的情况下，持续用力在指定平面上绘制圆形、椭圆形和数字8字形。在所有这些条件下以及所有受试者中，均观察到瞬时曲率与角速度之间以及瞬时曲率半径与切向速度之间存在显著的正相关；也就是说，当力轨迹的弯曲程度最大时，切向速度最低。这一发现与维维亚尼和特尔祖洛（1982年）在二维绘画手臂运动中获得的结果相似，并支持了中枢约束导致轨迹几何参数与运动学参数之间关系的观点。
