Slota Gregory P, Suh Moon Suk, Latash Mark L, Zatsiorsky Vladimir M
Kinesiology, Pennsylvania State University, University Park, PA 16802, USA.
J Mot Behav. 2012;44(3):169-78. doi: 10.1080/00222895.2012.665101. Epub 2012 Mar 28.
The objective of this study was to observe how the digits of the hand adjust to varying location of the center of mass (CoM) above or below the grasp and rotational inertia (RI) of a handheld object. Such manipulations do not immediately affect the equilibrium equations while stability control is affected. Participants were instructed to hold a handle, instrumented with 5 force-torque transducers and a 3-D rotational tilt sensor, while either the location of the CoM or the RI values were adjusted. On the whole, people use 2 mechanisms to adjust to the changed stability requirements; they increase the grip force and redistribute the total moment between the normal and tangential forces offsetting internal torques. The increase in grip force, an internal force, and offsetting internal torques allows for increases in joint and hand rotational apparent stiffness while not creating external forces-torques that would unbalance the equations of equilibrium.
本研究的目的是观察手部手指如何适应手持物体质心（CoM）在抓握上方或下方的不同位置以及转动惯量（RI）的变化。这种操作不会立即影响平衡方程，但会影响稳定性控制。参与者被要求握住一个装有5个力 - 扭矩传感器和一个三维旋转倾斜传感器的手柄，同时调整质心位置或转动惯量值。总体而言，人们使用两种机制来适应变化的稳定性要求；他们增加握力，并在法向力和切向力之间重新分配总力矩以抵消内部扭矩。握力（一种内力）的增加以及抵消内部扭矩，使得关节和手部的转动表观刚度增加，同时不会产生会使平衡方程失衡的外力 - 扭矩。
