Age-related osteoporotic hip fracture is a major medical problem whose incidence continues to increase. The comparison of populations from the same region who have about a two-fold difference in fracture incidence such as blacks and whites, and men and women, are likely to be useful models for elucidating the main factors responsible for fracture. These factors lie both in the components of bone strength at the hip, and in the determinants of the frequency and character of falls. Elderly blacks in central Indiana will be studied and the components of bone strength, the frequency of falls, the characterisitics of fall, muscle strength, tissue distribution around the hip and biochemical variables will be compared to those of a cohort of elderly whites who have already been studied from the same region using exactly the same methodology. Such a comparison will allow us to identify the main factors responsible for the different incidence of fracture in black and white men and women and develop from this information preventive measures applicable to both racial group and to both genders.