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Aims. - This article summarizes the literature on some of the biological mechanisms involved in Alzheimer disease and their evolution in the context of non-pharmacological interventions. Actuality. - Regular aerobic physical activity and enriched environment are two methods derived from the metabolic hypothesis and the cognitive enrichment hypothesis respectively. Their effects on aerobic fitness, cardiorespiratory function, brain structure and cognition are clearly established in the aging process in humans and animals. In the field of Alzheimer's disease, these methods might halt mitochondrial, amyloidogenic and tau pathophysiological development. Perspectives. - In elderly patients, the use of exergames (active video games) develops in order to make physicals activities more attractive. These new technologies, with high potential, would propose simultaneously aerobic activity in an enriched environment. Intervention research on the feasibility and the effects of these exergames for Alzheimer patients may be a way forward. Conclusion. - We propose to use serious (exer)games to stimulate Alzheimer patients. These serious games, being specifically developed for Alzheimer patients, would be to integrate high intensity aerobic activity and enriched environment into a ludic and accessible therapy.

The purpose of this study was to determine whether the excessive spikes observed in the surface electromyography (sEMG) spectrum recorded during whole-body vibration (WBV) exercises contain motion artifacts and/or reflex activity. The occurrence of motion artifacts was tested by electrical recordings of the patella. The involvement of reflex activity was investigated by analyzing the magnitude of the isolated spikes during changes in voluntary background muscle activity. Eighteen physically active volunteers performed static squats while the sEMG was measured of five lower limb muscles during vertical WBV using no load and an additional load of 33 kg. In order to record motion artifacts during WBV, a pair of electrodes was positioned on the patella with several layers of tape between skin and electrodes. Spectral analysis of the patella signal revealed recordings of motion artifacts as high peaks at the vibration frequency (fundamental) and marginal peaks at the multiple harmonics were observed. For the sEMG recordings, the root mean square of the spikes increased with increasing additional loads (p0.05), and was significantly correlated to the sEMG signal without the spikes of the respective muscle (r range: 0.54 - 0.92, p0.05). This finding indicates that reflex activity might be contained in the isolated spikes, as identical behavior has been found for stretch reflex responses evoked during direct vibration. In conclusion, the spikes visible in the sEMG spectrum during WBV exercises contain motion artifacts and possibly reflex activity. Key pointsThe spikes observed in the sEMG spectrum during WBV exercises contain motion artifacts and possibly reflex activityThe motion artifacts are more pronounced in the first spike than the following spikes in the sEMG spectrumReflex activity during WBV exercises is enhanced with an additional load of approximately 50% of the body mass.