In most studies, the study of the gait of cerebral palsy patients is done through quantified walking analysis tests, objectively evaluating the kinetic and kinematic parameters, associated with the measurement of respiratory exchanges and heart rate.~Nevertheless this very objective evaluation does not really reflect the child's ability to perform the acts of everyday life that he wishes, and in particular, his ability to walk a long time.~It therefore appears that patients do not only want to walk better on an objective and analytical level but also aim to walk longer and improve their walking efficiency.~To date, studies do not study the influence of external disturbing factors on the market.~The main hypothesis is that the stopping of walking in paralyzed cerebral patients is mainly due to an increase in the energy cost of walking.~The main objective is to confirm this hypothesis. The secondary objectives are to study the causes of the increase in the energy cost of walking (modification of muscle coordination / increase of co-activations, loss of strength, etc.).~For that, the investigators will use a tool that is perfectly adapted: the GRAIL (Real-Time Analysis Interactive Lab). The GRAIL uses an instrumented treadmill, a motion capture system (Vicon System), an electromyographic system as well as a virtual environment is projected on a 180 ° screen. This equipment allows patients to walk spontaneously or at prescribed speeds to a standstill in a virtual and secure virtual reality environment. Throughout the duration of the test, the investigators will quantify the evolution of biomechanical (kinematic, kinetic and EMG) and physiological (gas analysis system) factors during walking.~This is a study conducted in a usual evaluation framework: market analysis is commonly indicated for paralyzed children, in order to assess their disability and to propose the best therapy. There was no inherent risk in the proposed study protocol, but possible fatigue is inevitably analyzed, which is not related to inclusion in this study.
To date, studies do not study the influence of external disturbing factors on the market.~The main hypothesis is that the stopping of walking in paralyzed cerebral patients is mainly due to an increase in the energy cost of walking.~The secondary objectives are to study the causes of the increase in the energy cost of walking (modification of muscle coordination / increase of co-activations, loss of strength, etc.).~This study will use the GRAIL combining an instrumented treadmill, a motion capture system (Vicon System), an electromyographic system as well as a virtual environment projected on a 180 ° screen