Cerebral palsy is a neurological disease due to brain damage, (CP), it is the leading cause of pathological gaits in childhood. The Gross Motor Function Classification System (GMFCS) [1] is commonly used to classify the degree of motor impairments (5, levels). Several authors already studied the effects of the CP on the kinetics (GMFCS), the dynamic parameters of the musculo-skeletal system during gait. The results demonstrated that the profile is highly correlated with the GMFCS, the authors always observed abnormal pattern locomotion which could lead to increase energy consumption, gait instability, fatigue [