Materials and methods Twenty CP patients will be enrolled in the study. The inclusion criteria will be: bilateral lower limb (diplegic or tetraplegic) CP, 10 to 18 years of age, GMFCS levels II to IV, walk by themselves or with the use of an assistance device for at least 10 meters, maintain a sitting position without assistance and follow instructions and participate in the rehabilitative program. The exclusion criteria will be: lower limb spasticity >2 on the Modified Ashworth Scale, severe lower limb contractures, cardiovascular diseases, orthopedic surgery or neurosurgery in the past 12 months or Botulinum toxin and injections within 6 months before the beginning of the study.