Aim: To compare the 66-item Gross Motor Function Measure (GMFM-66) with the reduced version of the GMFM-66 (rGMFM-66) with respect to the detection of clinically relevant changes in gross motor function in children with cerebral palsy (CP).
Method: The study was a retrospective single centre analysis of children with CP who participated in a rehabilitation programme. Overall, 1352 pairs of GMFM-66 and rGMFM66 measurements with a time interval of 5 to 7 months were available.