Extended Data Fig. 7: Comparison with the full dataset of exercise-only controls.

Comparison with all exercise-only control participants who completed three months of aerobic and strength training, including 3 minors. Changes for the control group were computed by comparing pre- and post- 3 months exercise intervention data, while changes for the SCS group were computed by comparing pre-implant and post-explant data, except otherwise specified. a, Clinical assessments. HFMSE and 6MWT measured pre-implant, post-explant and 6 weeks follow up. In parenthesis changes from baseline measures. All tests executed with SCS OFF. 6MWT dropped back to pre-implant at 6 weeks follow up in 2/3 participants. b, Relationship between age and age of onset for exercise-only control group (black) and the participants in our study (blue). c, Histogram of HFMSE scores for the control group (black), blue lines represent the HFMSE scores for each SCS participant. d, Histogram of aerobic exercise time for the control group (black), and exercise time of each SCS participant (blue lines). e, left: Relationship between the change in 6MWT score and the HFMSE score for the controls (R² = 0.001) and the SCS participants (R² = 0.98). Right: Mean and 95%CI of the mean change in 6MWT score for the controls (black) and changes for SCS participants (blue). f, Left: Linear regression analysis between the change in fatigue index during the 6MWT and the severity for both the control group (R² = 0.15) and the SCS participants (R² = 0.7). Right: Mean and 95% CI of the mean change in fatigue index across controls (black) and changes for SCS participants (blue) g, left: Regression analysis between the change in stride length and severity for controls (R² = 0.01), blue dots indicate SCS participants. Right: Mean change in stride length for the controls (black), and changes for SCS participants (blue). h, Same as g for stride velocity (R² = 0.07). For the SCS participants, changes were computed during self-paced overground walking, comparing SCS OFF trials from week 1 and week 4. i, Left: Regression analysis between the change in knee flexion strength for the controls (R² = 0.05). Improvements for SMA01 and SMA03 and their confidence intervals are shown in blue. Right: Mean knee flexion strength for the controls (black) and SCS participants (blue). j, Same as i for knee extension (R² = 0.48). Error bars represent the 95% confidence interval of the mean, computed with bootstrapping (N = 1000).