Fig. 1.

Schematic overview of the step targets and their shifts in forward–backward direction

(Adapted from Mazaheri et al. 2015). The distance between the step targets was determined based on participant’s preferred step length. At random moments (separated by 5–7 non-shifted steps), a step target could shift forwards (+ 40% of step length) or backwards (− 40% of step length), requiring a longer step (a) or shorter-step (b) response. The shift targeted either the right or left leg