Fig. 1

Illustration of the experimental setup for the postural stability test. The participant stands on a plantar pressure mat, facing a large projection screen. The field of view is limited to the screen by asking the participant to wear a pair of goggles. The head motion is simultaneously tracked by a motion tracking system with a marker placed at eye level. The screen displays a cloud of random dots with simulated motion in the depth direction to perturb the standing posture in the anteroposterior (AP) direction