Fig. 5.
Action test: relations between digit forces and center of pressure. A, B, E, F: correlations between the difference in digit load force (dLF) and relative digit positions (dy) for active (A and E) and passive conditions (B and F). C, D, G, H: correlations between average grip force (FGF) and dy for active (C and G) and passive conditions (D and H). Data from all trials and subjects are plotted for each condition (group 1: 18 trials × 15 subjects = 270; group 2: 18 trials × 8 subjects = 144) and expressed in normalized form (see text for details). Larger values of dLF and dy correspond to the larger normalized values within the condition per digit position, and vice versa for the smaller values. The coefficient of determination (R2) and corresponding P value are shown in each plot.