Several clinical trials assessing children with hereditary neuromuscular disorders have been performed over the last decade. These studies highlighted issues related to design and performance of clinical studies assessing children with this group of disorders. This article reviews recent literature and clinical experience in this area, highlighting methodological shortcomings and disease-specific clinical confounding factors that should be considered for future study design. The state of the art of outcome measures in neuromuscular disorders will be discussed, and suggestions for future clinical trials are presented.