If we chose a nominal speed and perturbation type we have a distribution of gains across subjects. Rouse 2014 used an ANOVA (I'm guessing) to compute whether the gains are significantly different from the others at different gait phase points. So given the mean scheduled gain (e.g. proportional ankle) across subjects, are the gain values different from those at each schedule. A post hoc analysis can then be used to see which schedules are the same and different.