RecruitingClinical trialCharacterizing Perceived Physical Fatigability in Nusinersen-treated SMAThe purpose of this project is to investigate the utility of the SMA EFFORT, an SMA-specific patient-reported outcome measure, to assess perceived physical fatigability that is anchored to intensity and duration of activities. We aim to characterize perceived physical fatigability (PPF) in a diverse cohort of people with SMA (pwSMA) and evaluate the change of PPF before and after nusinersen dosing.