• 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. [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  

• changes in : physical functional capacity, global physical activity level, feeling of self-efficacy, and general physical and psychological well-being. [ Time Frame: 1 year and 2 years ] [ Designated as safety issue: No ]
  

Background : Osteoporotic fractures are a major cause of morbidity and disability in elderly women. Most of these fractures result from a fall. Falls prevention measures largely applicable in the population may contribute to significantly reduce the number of fractures in the population. Recent randomized controlled trials have shown that exercise programs of relatively low intensity, but centered on balance retraining and targeted to subjects at moderate risk, can reduce the risk of falls by 15 - 50% in community-dwelling elderly people. But, the effectiveness of exercise in protecting against the most serious falls, especially those accompanied by fractures, has not been demonstrated.

Objectives : To evaluate the effectiveness of exercise for prevention of falls accompanied by fractures or other serious physical traumas. Also, to better understand the mechanisms by which physical exercise prevents falls and fractures (improvement in physical functional abilities, global physical activity level, general physical and mental health, and self-confidence), and to determine the individual factors associated with a good long-term adherence to the program.

Method : Randomized controlled trial. Participants will be women aged 75 years or older, living at home, and with impaired physical functional capacity (as assessed by simple functional tests). Women will be recruited using general population lists, such as voter-registration or supplemental health-insurance membership rolls. They will be randomized in 2 groups : one that will receive the intervention, and a control group without it. Each group will include 1000 women followed for 2 years, which will allow to demonstrate a 30% reduction in the frequency of serious falls in the intervention group (if the incidence of serious falls is around 8% per year). Falls and injuries occurrence will be monitored by asking women to return monthly calendar cards where they can mark the date of any falls. A telephone interview will then be realized in case a fall is reported.

Intervention : The intervention will last 2 years and will be implemented in partnership with the association SIEL (Sport, Initiatives, et Loisir) Bleu in 25 centers located in large and medium-sized cities. It will include weekly exercise sessions in small groups, led by a qualified and specially trained instructor, and supplemented by simple exercises to do at home.

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). Falls associated with an intrinsic major event or an overwhelming hazard 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 (balance, gait, reaction time, muscle strength), global physical activity level, feeling of self-efficacy (fear of falling), and general physical and psychological well-being. These changes will be evaluated on a sample of participants (160 per group) that will be re-examined at 1 year and 2 years.

Expected results : The group intervention that we propose to assess is relatively simple to implement. It relies on a network of participants already established across France. In case of a demonstrated benefit it could therefore be easily generalized as part of a population-based public health program of falls and fractures prevention in the elderly. The intervention should enable elderly women to preserve two elements essential to their quality of life as they age, that is, their functional capacity and their independence.