Body Weight as a Criterion in Judging Bone Mineral Adequacy

Abstract

APART from the extreme criterion of bone fracture, there is no definitive measurement of bone adequacy in terms of strength in relation to function. Comparison of bone mineral is usually made on the basis of age¹ or sex² without regard to the size or the physical status of the individual. This is in spite of Galileo's observation that the weight of a body is a function of the cube of its diameter whereas the strength of a bone is a function of the square of its diameter³. Galileo also conceived that a constant sized bone would support more weight if it were made of a stronger material, but did not seem to be aware that bones are subject to change in density. This is rather surprising as he discussed at some length the density of various substances. We now know that bone density varies and that the strength of both trabecular⁴ and cortical bone⁵ increases with density.