Single-session reliability of discrete gait parameters in ambulatory children with cerebral palsy based on GMFCS level.

The single-session reliability of 28 discrete spatiotemporal and kinematic variables was evaluated from computerized gait analysis (CGA) in 33 ambulatory children with cerebral palsy (CP), subcategorized according to Gross Motor Function Classification System (GMFCS) Levels I (n=11), II (n=12) and III (n=10). Nineteen boys and 14 girls participated, mean age=8 years 1 month (S.D.=3 years 0 month). Intraclass correlation coefficients (ICCs) estimated reliability, and the number of strides required to obtain an ICC of at least 0.90 was determined. The reliability of discrete gait parameters was dependent upon GMFCS level, with children in GMFCS Level I exhibiting the highest reliability (ICC range=0.70-0.96). GMFCS Levels II and III had lower levels of reliability with ICC values varying from 0.54 to 0.95 and 0.45 to 0.98, respectively. With the exclusion of pelvis range of motion (ROM), an average of four strides provided a reliability estimate of at least 0.90 for GMFCS Level I, while six strides were needed for children in Levels II and III. On the basis of the intrasession reliability results from the present study, further work is recommended to examine the test-retest reliability of these gait parameters in children with CP.