A crossover repeated measures design was employed in this study. Sixteen children with CP were randomly divided into two groups. One group received an 8-week WMV intervention followed by an 8-week control condition, with a 4-week rest in between ; the other group began their treatment sequence with the control condition to counterbalance the order effects(Fig. 1). The outcome variables included active and passive range-of-motion (AROM and PROM) of both knees, relaxation index (RI) assessed by the Wartenburg Pendulum test, modified Ashworth scales (MAS) for bilateral knee extensors, timed up-and-go (TUG) and 6-min walk test (6WMT)