How we Measure Bone Health
Currently there is no practical measure of bone strength. Bone mineral density (BMD) is used as a proxy measure of bone strength. Mineral density accounts for about 70 percent of bone strength. The World Health Organization (WHO) defines osteoporosis in women as a BMD that is 2.5 standard deviations below the mean of a young white adult female. There is ongoing discussion as how to apply this criterion to men, children and across ethnic groups. Because of difficulties in obtaining accurate measurements of mineral density and of standardization between instruments and bone sites, controversy exists among experts regarding the continued use of this diagnostic criterion.