Inclusion Criteria:  Confirmed diagnosis of spastic cerebral palsy or patients at high-risk for spastic cerebral palsy Suspected GMFCS levels I-III (GMFCS = Gross Motor Function Classification Scale, expressing the overall functional level of impairment)  Exclusion Criteria:  Non-ambulatory Botulinum neurotoxin type-A injections six months prior to enrollment Lower limb surgery two years prior to enrollment Muscle surgery at the muscles in the lower limb Selective dorsal rhizotomy as treatment history Presence of ataxia or dystonia Severe co-morbidities (severe epilepsy, severe behavior problems that impede the cooperation)