Fig. 3
From: Amplitude and frequency of human gait synchronization with a machine oscillator system
Example trial. The TVA Experiment is shown for \({\Delta }f_{m} = + 6\% f_{p}\). (A) Step frequency over time (fs, magenta), begins near baseline preferred and drifts toward motor frequency (fm, blue) during synchronization. (B) Motor amplitude (Am) shown in red (left axis) and the positive (i.e., pulling upward) measured impulse (Jc) relative to baseline plotted in light blue (right axis). (C) Mean active force oscillation (± 1 standard deviation) plotted for Am = 20, 30% BW, and all traces shown for Am = 10% BW, since force alignment is inconsistent sans synchronization. Force signal commanded to motors (grey dashed), shown for comparison to measured forces. Force curves are associated with data outlined in boxes in (A) and (B), labeled (i), (ii) and (iii). Alignment of force oscillations relative to double stance (DS) and middle stance (MS) is viewed relative to the step cycle.
