Evaluation criteria : The main outcome measure will be the incidence of serious falls defined as " an unexpected event in which the participant comes to rest on the ground, floor, or lower level " and accompanied by a fracture or another serious injury (including head injuries requiring hospitalization, joint dislocations, severe sprains, other non-specified serious joint injuries, and lacerations requiring suturing) (Buchner DM et al 1993). The effectiveness of the intervention on all injurious falls including those leading to more moderate injuries (such as bruises, cuts, abrasions or reduction in physical function for at least 3 days, or if the participant sought medical help (Campbell AJ et al 1997) will also be assessed. Falls associated with an intrinsic major event or an overwhelming hazard (e.g., traffic accident) will be excluded. Intermediate outcome measures, which may help to explain the effect (or absence of effect) of the intervention, will be changes in physical functional capacity (e.g., balance, gait), global physical activity level, feeling of self-efficacy (fear of falling), and general physical and psychological well-being (quality of life). These changes will be evaluated on a sample of participants (160 per group) that will be re-examined at 1 year and 2 years.