Botulinum Neurotoxin for Children With CP: a Delicate Balance Between Clinical Benefits and Muscular Harm

\- Children with spastic cerebral palsy Inclusion criteria: * Children (boys/girls) with congenital brain lesion, confirmed with neuro-imaging such as MRI * At high-risk for CP or diagnosed spastic type of CP * (Suspected) Gross Motor Function Classification Scale (GMFCS) Level I-III * Uni or bilateral involvement * Aged between 2-16 years Exclusion criteria: * Presence of dyskinesia or ataxia * Severe co-morbidities (cognitive problems) * BTX treatment in the gastrocnemius in the past 10 months * Previous surgery at the investigated muscles. * Previous orthopedic or neurosurgery * Severe ankle deformities * Weight for height values \>2SD or \<-2SD from mean * Typically developing children Inclusion criteria: • Aged between 2-16 years Exclusion criteria: * History of neurological, orthopedic or muscular problems * Involvement in an elite or high-performance sporting program (Children performing the same sports for \> 5 hours/week will be excluded)