The purposes of this study were to compare the arm movements of persons with and without cerebral palsy and to determine if the alteration of the seat angle of a chair affected the quality of those movements. Twelve subjects—3 men and 3 women with spastic cerebral palsy and 3 men and 3 women without any known anomalies that could affect arm movements—were studied. The number of movement elements constituting a reach was used to measure the quality of movements. The findings demonstrated significant differences in the number of movement elements used by the subjects with and without cerebral palsy regardless of position. No significant differences could be attributed to the seating positions. Implications are discussed in relation to the method used in the analysis of movements and the effect of the findings for research and treatment.