Fig. 10
Comparison of muscle effort in three conditions: passive, transparent and without exoskeleton. The average muscle effort (time integral of the muscle activity) is shown relative to the transparent condition by the gray bars and the corresponding standard deviation across all fifteen participants is shown by the error bars. Each muscle is scaled separately relative to the corresponding average muscle effort in the transparent condition. The black dotted line represents this relative muscle activity in the transparent condition, scaled to one. In the left subfigure (a) the muscle effort of the passive condition is compared to the transparent condition. In the right subfigure (b) the effort of the condition without exoskeleton is compared to the transparent condition. When the plotted bars and error bars lie above one, the muscle effort is larger than in the transparent condition. Significant differences between the without exoskeleton and transparent condition are marked with a black star (pBonferroni−Holm<0.05)