Ankle-foot Orthoses for Night Splinting in Children With CP: Impact on Passive Stiffness in Plantarflexors Muscles

Inclusion Criteria: * Children diagnosed spastic cerebral palsy * Children wearing night splint ankle foot orthoses all night long during 1 week minimum * Children with a level of spasticity in the gastrocnemius muscle greater than or equal to X1, VII, on the Tardieu scale and 2 on the Ashworth scale. * Children able to understand and respect the simple instructions of the study * Children and parents who received informed information about the study and who co-signed, with the investigator, a consent to participate in the study. Exclusion Criteria: * Children who do not tolerate ankle foot orthoses all night long. * Children who had botulinum injection in gastrocnemius or soleus muscles during last three months. * Children benefiting from an injection of botulinum toxin or the setting up of new equipment during the protocol. * Children who do not tolerate ankle foot orthoses all night long. * Children having benefited from plaster lengthening for less than three months.