Background: The cerebellum is crucial for motor control (e.g. of gait and posture) and motor learning. Therefore, motor rehabilitation in patients with degenerative cerebellar disease is challenging, and the capability of motor improvements for these patients is not fully understood. We have recently shown, that a 8 weeks motor training program based on playing whole-body controlled video games can lead to a reduction of ataxia symptoms and an improvement in gait in children with degenerative cerebellar disease (Ilg 2012). In this study, we examined quantitatively, whether this motor training leads to - specific improvements in motor control of complex whole-body movements, which are relevant in everyday life and which cannot be explained simply by improvements in general fitness Methods: To assess the specific effects of motor training, we analyzed the movement behavior during playing the Xbox Kinect™ game “Light Race” of 10 children with degenerative cerebellar disease versus 10 age-matched controls. Here, subjects have to control an avatar performing one minute sequences of rapid stepping movements towards different goals. Cerebellar children were tested in this game before and after an 8 weeks training program including different video games focusing on dynamic balance, trunk-limb coordination and goal-directed movements. The rapid stepping sequences during game playing were analyzed with respect to dynamic stability (Hof 2005), multi-joint coordination, anticipatory postural adjustments and movement variability. Results: After 8 weeks training, children improved their general game play with respect to games scores, increased averaged velocity and dynamic stability. In addition, specific measures revealed (a) improved anticipatory postural adjustments before stepping (p=0.04), (b) decreased movement decomposition (p=0.01), (c) decreased movement variability during stepping (p=0.04) as well as increased dynamic stability at the end of the stepping movements (p=0.01). Conclusion: Despite progressive cerebellar degeneration children are able to improve specific aspects of motor performance in complex whole-body movements which are relevant in everyday life (e.g. rapid stepping movements to compensate for gait perturbations). Therefore, directed training of whole-body controlled video games present a highly motivational, cost-efficient and home-based rehabilitation strategy to train dynamic balance, multi-joint coordination and interaction with dynamic environments in a large variety of young-onset neurological conditions. References: Hof A, et al. J Biomech 38: 1-8, 2005. Ilg W, et al. Neurology 79: 2056-2060, 2012.