Introduction.
Serious games (SG) combined with virtual or augmented reality technologies are used to improve gait parameters for children with cerebral palsy (CP). We have developed a SG using the Microsoft Hololens augmented reality headset called ARRoW-CP, which integrates motor learning theories3 and audio-visual feedback to perform a 4-week intensive overground gait training (OGT) for children with CP.

Methods.
This work followed the development framework PROGame5 within a multidisciplinary team. Regular user tests with therapists and patients were conducted to be as close as possible to their needs. Key steps of the project included:
1. A validity study of the algorithm measuring spatiotemporal gait parameters with the AR headset
2. An experimental study to determine the best combination of feedback modalities to achieve maximum walking speed (WS)
3. A randomized control trial (in progress) including children with CP. They participate in a four-week OGT with ARRoW-CP vs. treadmill training. Outcomes are the 6-minutes-walk test and the Muscle-Power-Sprint-Test, which assess functional capacity and anaerobic performance.

Results.
First qualitative results (N=5) show a significant improvement for 6MWT and MPST. Enjoyment and motivation are higher in the ARRoW-CP group. Children present a linear progression in WS between each session and weeks.

Discussion and Conclusion.
ARRoW-CP combines multiple ingredients of motor learning theories3: context focused therapy, goal-directed training,10 task-specific, variable practice, high intensity, feedback during therapy sessions and motivation of the patient.11 Preliminary results are very positive, we plan to include 40 patients to test our rehabilitation programme and the benefits of our SG.

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