Guillot, Asress, Richardson, Glass, and Miller (2008) recently reported that treadmill gait analysis does not detect motor deficits in animal models of Parkinson's disease (PD) or amyotrophic lateral sclerosis (ALS). The authors studied aged C57BL/6J mice administered the neurotoxin 1-methyl 4-phenyl 1-, 2-, 3-, 6-tetrahydropyridine to model PD, and a small number of presymptomatic superoxide dismutase 1 G93A mice to study ALS. Several key issues merit discussion to put their observations in perspective. An increasing number of research groups are applying treadmill gait analysis to their rodent models of numerous movement disorders. The conclusions Guillot et al. drew undermine the potential importance of the paradigm of treadmill gait analysis for understanding and treating PD and ALS.