A Pilot Study of the Effect of Botulinum Toxin Type a (Dysport®, Abobotulinum Toxin A) Injection on Changes in Musculotendinous Length and Dynamics of Hamstring Muscles During Gait in Children With Spastic Cerebral Palsy Walking With Excessive Knee Flexion

"1. BoNT-A will be injected into two hamstring and/or gastrocnemius muscles under the guidance of ultrasonography or electrical stimulation.~2. Maximal total dose and dose regimen for each muscle would follow the recommendation of international consensus.~A. Semitendinosus 5 to 7.5 units/kg of body weight B. Semimembranosus 5 to 7.5 units/kg of body weight C. Gastrocnemius 10 units/kg of body weight D. Maximal total dose per patient : unilateral injection 500 units, bilateral injection 1,000 units E. The dosage of two hamstring muscles will depend on the severity of spasticity and gait abnormalities of children with CP"