Habitual physical inertia and other factors in relation to risk of fracture of the proximal femur.

Physical inactivity is associated with low bone mass in adults, and might therefore be a risk factor for proximal femoral fracture in old age. This hypothesis was tested in a case-control study of 139 selected patients with confirmed proximal femoral fracture and 139 age- and sex-matched community controls, using an interviewer-administered questionnaire. Patients had been significantly less physically active in middle age than had controls, a difference that was greater in the younger subjects. It is suggested that the progressive decrease during the present century in the amount of physical activity associated with everyday life has resulted in increased numbers of elderly people being at risk of femoral fracture and may be the cause of the rises in age-specific incidence rates now being observed. If this explanation is correct, a planned increase in leisure-time physical activity in middle age and beyond may be the most effective method of preventing these fractures.