At IRAHM, each child benefits of 3 physiotherapy sessions and 2 occupational therapy sessions per week. Each session lasts 45 minutes. The children in the control group will see no change in their treatment. In the experimental group, 1 physiotherapy session and 1 occupational therapy session will be replaced by two sessions of intensive rehabilitation of the arm with the robot. In total for each group, each child will benefit from 40 sessions of 45 minutes over 8 weeks therapy