- To develop a method of quantifying the features of cycling in children with CP by comparing them to typically developed children, and to demonstrate the applications of this tool for evaluating treatment effects in children with CP. Twenty-seven typically developed children and 51 with CP, classified by their gross motor function levels, were studied. Angular velocities were measured during self-paced active cycling and during passive cycling imposed by an electrically powered stationary cycle. Angular velocities were compared with the gross motor function levels, Modified Ashworth Scale and the Adductor Tone Rating. Significant differences between children with CP and those typically developed demonstrated in passive mode that the cycling task is sensitive to differences in resistance offered by the subjects. Active and passive cycling velocities differ significantly between groups classified by their functional levels (p < 0.01). Children with CP in the mild group showed no differences from typically developed children. The correlations between passive cycling and clinical tests were significant and higher at higher speeds (r = 0.62). Correlations with anthropometric measurements for the typically developed group associated the cycling task with growth and development, and for children with CP with motor control adjustments and impairments. Measuring of these two cycling modes could be applicable in assessing lower extremity function in children with CP and changes following interventions.