We compared the timed performance and compensatory movements of 32 boys (mean age = 10.0 years) with Duchenne muscular dystrophy (DMD) and 38 healthy boys (mean age = 9.2 years) on 10 -meter walking and four-step stair work (climbing and descending). Dependent measures were digital scores on the Functional Evaluation Scale for DMD obtained by watching the boys on film. Groups were compared initially and after 6 and 12 months, using General Linear Models analysis (for two groups and three assessments). Results showed no significant timed performance differences between groups on 10 -m walking at the initial assessment; but boys with DMD showed longer times after 6 and 12 months, and boys with DMD engaged in more compensatory movements while walking. For stair climbing, boys with DMD were significantly slower than healthy controls when both climbing and descending steps in all assessments.