patients are treated with 20 sessions of GRAIL rehabilitation, associated to 20 traditional physiotherapy sessions (1+1 a day, during a period of 30 days)

subjects are treated with 40 sessions of traditional physiotherapy (2 a day, during a period of 30 days)

each subjects included in the intervention group will receive 20 GRAIL sessions, aimed to the walking pattern improvement, associated with 20 traditional physiotherapy sessions, aimed to the stabilization of the trained competences

Analysis of the walking pattern performed with traditional gait analysis lab and with GRAIL system

Assessment of the kinetic function, divided into 5 dimensions, range from 0 to 88, 0 meaning worse scores and 88 healthy subjects.

recording of the distance run by the patient in a lapse of time of 6 minutes

Questionaire Filled in by the patients or by the parents, on the perception of the walking ability, range from 1 (subjects unable to step) to 10 (healthy subjects)