FIGURE 1.

(A) Participants walked on a split-belt treadmill with a speed ratio 1/3 between the slow and the fast leg during the adaptation phase. Namely, the faster belt moved at the maximal speed obtained during the 25FWT and the slower belt always moved at the 1/3 of that speed. Gait parameters where recorded using sensor insoles. (B) Each session consisted of three phases (baseline, adaptation, and postadaptation). The clinically less affected leg (people with MS) or the dominant leg (controls) walked on the fast belt. During the baseline period, subjects walked with both belts tied at a slow speed for 5 min. During the adaptation period, they walked for 15 min in a split-belt condition, with one leg moving fast and the other slow. During the postadaptation period, subjects walked for 10 min with both belts tied at the slow speed. This training was repeated 24 h (T1) and 72 h (T2) after the first session. (C) In experiment 2, participants received anodal or sham tDCS over the cerebellum ipsilateral to the less affected/dominant leg immediately after the adaptation phase at T0 only. On the following days, the experiment was performed without tDCS.