Assessment of fatigability in patients with spinal muscular atrophy: development and content validity of a set of endurance tests

Fatigability has emerged as an important dimension of physical impairment in patients with Spinal Muscular Atrophy (SMA). At present reliable and valid outcome measures for both mildly and severely affected patients are lacking. Therefore the primary aim of this study is the development of clinical outcome measures for fatigability in patients with SMA across the range of severity. We developed a set of endurance tests using five methodological...