Fig. 6

Example of AO results during the trial of one healthy subject walking at variable gait velocity. A Compares the AO phase estimation (solid orange line) with the offline phase calculated based on the heel strike detected by the insole pressure sensors (dashed cyan line) during a trial segment. B The median phase estimation during a step in the trial and median error during the step; areas represent the 10th–90th percentiles. C Compares the gait frequency estimated by the AO in real-time (solid orange line) with the gait frequency calculated offline based on heel strikes (dashed cyan line) during the trial. For all the panels, purple lines show the error between the AO estimation and the offline result and are represented with respect to the right axis