Figure 3.

(A) Retention group: step symmetry (SS) across 600 strides of the split-belt conditions on day 1 (orange) and day 2 (blue) overlaid. Solid lines with shaded area are mean ± SE. Closed symbols show final (last 20 strides) of step symmetry for day 1 learning. (B) Re-learning group data plotted as in A. Open symbols show step symmetry prior to re-learning (last 20 strides of washout). Note that the curves overlap for the two youngest groups, indicating no improvement in re-learning. (C) Difference across days (day 2—day 1) in step symmetry during early adaptation (first 20 strides of split-belt walking) for the Retention group. (D) Difference in step symmetry for the Re-learning group plotted as in C. The two youngest age groups were significantly different from the oldest age group (see main text).