Fig. 1.

Platform perturbation overview. Perturbations varied in magnitude, direction and timing. (A) Magnitude included 5, 10 and 15 cm displacements of the ground underneath the participant. These overall displacement values were accompanied by changes in peak velocity and acceleration, as shown. (B) Direction included platform slides in the anteroposterior, mediolateral and corresponding diagonal directions. (C) Timing of the perturbation onset included double stance as well as early, mid and late single stance. Together, the complete combination of all these independent variables resulted in 96 unique conditions (3 magnitudes×8 directions×4 timings).