Fig. 1.

A and B: experimental protocol illustrating the Vertical Active (A) and Vertical Rest (B) conditions of the main experiment. Arrow indicates a 45° upward arm movement. Gray T (B) represents the support for the outstretched arm. Black disks indicate the initial and final positions of the target. C: experimental protocol illustrating control experiment 3. Arrow indicates a 45° rightward arm movement. Gray cube represents the masses used to generate vertical shoulder torques. Black disks indicate the initial and final positions of the target.