Objective: The aim of this study was to establish a rehabilitation program for patients with cerebellum-based postural ataxia. Physiotherapists report symptomatic improvements in patients presenting motor disorders after a training program consisting of standing on a moving force platform. Methods: In our program healthy subjects (CTRL) and cerebellar patients (CBL) were subjected to sinusoidal stimulation movements lasting 3 min and repeated 8 times. Between stimulations subjects had to perform blocks of 20 fast or precise sidesteps to quantify any improvement. During these manoeuvres the trajectories of the center of vertical pressure (CVP) was derived from the forces, exerted by the subjects on the platform. For comparison during the dynamic section of the step time and amplitude were normalized and derivatives were calculated. Results: CTRL showed characteristic centre-weighted, symmetric, three-peak velocity curves whereas CBL presented unsymmetric profiles with multiple peaks. Precise sidesteps were clearly more difficult than fast sidesteps for both CTRL and CBL. However, CTRL showed a clear difference in the duration and in the time course between fast and precise steps which was less pronounced in CBL. The variation of the CVP trajectory and its derivatives was clearly smaller in CTRL although some CBL showed a reduction of the variation, smoother courses and more symmetric velocity profiles indicating a general improvement at the end of the whole session. These observations coincide with reports of the CBL who scored their condition during the week following our training program. Conclusion: The temporarily reduced postural-based ataxia and the subjective estimation of their general and their motor specific state of CBL allow us to hope that an improvement may be obtained by simple physical treatment. Supported by Else-Kröner-Fresenius Stiftung (A12/07)