Cerebral palsy (CP) has been described as a group of disorders of the development of movement and posture that are attributed to nonprogressive disturbances that occurred in the developing fetal or infant brain. Diseases of the peripheral nerves/ spinal cord (e.g., spinal muscular atrophy, myelomeningocele) or muscles (e.g., muscular dystrophies), although they may cause early motor abnormalities, are typically not considered CP.