Figure 2.

Typical hand pose combinations observed in each experimental condition. A: in the fixed-base condition, subjects displayed more diversity in their hand poses. 1: in most cases, one hand (right hand) rotated the screwdriver, and the other hand (left hand) assisted manipulation by stabilizing the screwdriver. 2: in other cases, the fingers of the two hands moved in coordination, while the right finger provided stabilization. 3: in a few trials, subjects used only one hand. B: in the free-base condition the dominant (right) hand typically controlled the screwdriver and the nondominant (left) hand stabilized the watch face.