Figure 2.

Mean COP position along the antero-posterior axis at three different periods for the no-vibration (vision and no-vision) and vibration (Achilles and tibialis anterior) conditions. The mean COP was calculated for the three 500-ms periods (i.e., before the vibration, before the onset of the pointing movement and at the end of the movement). Positive values indicate a forward COP position with reference to baseline values (that is, once a participant adopted the initial posture and showed a stable COP position within the first 4 s). Negative values indicate a backward COP position with reference to baseline values.