Fig. 3

(LEFT) Average left and right leg moment output over time from each stimulation condition, normalized to participant body weight. Dashed vertical lines indicate average time to fatigue (TF) below 0.135 Nm/kg (dashed horizontal line). Dotted vertical lines indicate average time below target (TBT) knee moment, 0.3 Nm/kg. (RIGHT) Comparison of outcome measures from constant, open-loop SOPS, and closed-loop SOPS stimulation trials. Bar height indicates left and right leg mean. Error bars indicate standard deviation. Closed-loop SOPS increases time below target (TBT, upper left). Both SOPS paradigms increase total work (W, bottom left) and time to fatigue (TF, upper right) over constant stimulation. Arrow indicates closed-loop SOPS did not fall below TF value by the end of the trial for either leg. Ripple index (R, bottom right) was significantly higher with open-loop SOPS compared to the other conditions. No significant difference in ripple was found between constant and closed-loop SOPS