The prevention of fractures in the elderly population has become a primary objective of public health because of the costs involved, in both economic and social terms. The present effective method for measuring bone mass has called attention to the relationship between osteoporosis and the risk of fracture. A reduction in bone mass is a determining factor, but not in itself sufficient for an overall understanding of the problem. This study collates anatomical, physiological, biomechanical and epidemiological data, which makes it possible to evaluate the different factors involved in predicting fractures in subjects affected with osteoporosis.