The goal of this study was to investigate the conjoint changes of digit forces/moments in three dimensions during static prehension under external torques acting on the object in one plane. The experimental paradigm was similar to holding a book vertically in the air where the center of mass of the book is located farther from the hand than the points of digit contacts. Three force and three moment components from each digit were recorded during static prehension of a customized handle. Subjects produced forces and moments in all three directions although the external torques were exerted on the hand-held object about only the Z-axis. The three-dimensional response to a two-dimensional task was explained by the cause-effect chain effects prompted by the non-collinearity of the normal forces of the thumb and the four fingers (represented by the virtual finger). Because the force are not collinear (not along the same line), they generate moments of force about X and Y axes that are negated by the finger forces along Y and X directions. The magnitudes of forces produced by lateral fingers (index and little) with longer moment arms were larger compared to the central fingers (middle and ring). At the virtual finger (an imaginary digit whose mechanical action is equivalent to the summed action of the four fingers) level, the relative contribution of different fractions of the resistive moment produced by subjects did not depend on the torque magnitude. We conclude that the CNS (a) solves a planar prehension task by producing forces and moments in all three directions, (b) utilizes mechanical advantage of fingers, and (c) shares the total torque among finger forces and moments in a particular way disregarding the torque magnitude.