Physical activity limits the effects of age and Alzheimer's disease on postural control.

The aim was to study the possible influence of physical activity on the postural performance of subjects with Alzheimer's disease (AD). The postural performance (i.e. surface area of the center of foot pressure displacement) of 3 groups was compared: Alzheimer active group (AA), Alzheimer non-active group (ANA) and healthy non-active group (HNA). The AA group's postural performance was superior to that of the ANA and HNA groups. AD disturbed postural performance but participation in regular physical activity made it possible to limit the disturbing effects of AD to a surprising extent, since the postural performance of active AD subjects was also superior to that of healthy subjects.

The impact of time of day on the gait and balance control of Alzheimer's patients.

Alzheimer's patients suffer from circadian dysregulation. The aim of this study was to examine the evolution of balance control and gait at different times of the day (11:00, 14:00, 18:00) in order to identify whether Alzheimer's patients were more likely to fall at certain periods of the day. Spatio-temporal parameters of centre of foot pressure displacements were measured with a force platform and spatio-temporal parameters of walking were evaluated with a gait analysis device. The results highlighted that balance control was worse in the evening and the afternoon than in the morning. Furthermore, the walking speed was faster and support duration, swing duration and cycle duration were shorter in the evening than in the morning and afternoon. The combined analysis of balance control and gait parameters revealed that balance control and walking are concomitantly altered in the evening which increases the fall risk in the evening, in comparison with the morning, for Alzheimer's patients.