CoP lateral displacement.

<p>Lateral CoP recorded during stepping for a representative trial (left panel). Mean amplitude and duration of both the thrust and the subsequent unloading component of the APAs (right panel). ns: p>0.05, *p<0.05, **p<0.01, ***p<0.001.</p

Undetected platform translation and cutaneous threshold. (

<p>A) Mean percentage of undetected translations of all subjects. (B) mean cutaneous threshold of the three areas of the foot sole surface in contact with the ground during gait initiation. ns: p>0.05, *p<0.05.</p

Shear forces and head acceleration.

<p>(A) lateral forces recorded during quiet standing position for a representative trial. The amplitude of the force was computed from the translation onset to the peak of the first shear force. (B) mean amplitude of lateral (shear) forces measured at the maximal peak force evoked by the platform translation when the participants were standing still or preparing to step forward. (C) head acceleration recorded during quiet standing position for the same represenative trial as above. (D) mean head accelerations measured at the time to peak force. ns: p>0.05, **p<0.01, ***p<0.001.</p

Results of source reconstruction from the grand average EEG data of the 6 participants (Low Resolution Electromagnetic Tomography, sLORETA) displayed on the used source space (Montreal warp brain aligned to the co-ordinate system of Talairach and Tournaux).

<p>sLORETA images depicted the estimated current density strengh corresponding to the effect of translation relative to baseline (Translation minus Stationary) for the Late SEP. The scale of the maps was chosen to maximize identification of the sources and were given a marked threshold to only show source activity that was 18% upper of minimal activation. Note the clearly distinguishable activation above the primary somatosensory cortice (top view) and the right posterior parietal cortex (e.g., VIP) and the Temporoparietal region.</p

SEPs recordings. Grand-Average for 6 participants recorded at electrode Cz for the Stationnary standing condition (Top panel), Translation standing and Translation stepping conditions (Bottom panel).

<p>The vertical dotted lines indicate the vibration onset and offset, the second vertical dotted line also indicates imperative tone stimulus for step execution. For both Translation conditions, the vertical dash-dotted line indicates the translation onset (occurring 500 ms before vibration). The “foot-off” indicates the onset of the stepping movement computed on the foot vertical velocity. The scalp topography was shown at the peak negativity for the participants average in the Sationary and Translation conditions.</p

Mean P1-N1 SEP amplitude of each participant (P1–P6) for the Stationary and Translation platform conditions (upper panel).

<p>Normalized attenuation for the translation condition relative to the Stationary condition (bottom panel). The mean attenuation for the 6 participants was of 21% (±6). <b>B:</b> Mean amplitudes for 6 participants of the P1-N1 early SEP and mean integral of EEG activity (iEEG, late SEP) computed in a time window comprising between early SEP ending until 600 ms (*: p<0.05).</p

Experimental set-up and mean lateral platform acceleration (left scale and red curve) and head acceleration (right scale and black curve) during Translation standing condition for the 6 participants.

<p>The onset and offset of head acceleration and deceleration, respectively, were indicated by the arrows according to the vestibular threshold (horizontal dotted lines). <b>B:</b> Mean platform and head accelerations for each of the 6 participants.</p