With more people than ever reaching greater age, clinicians, as well as scientists and family doctors, have development an increasing interest in osteoporosis. One of the biggest difficulties facing the medical profession today in the area of osteoporosis is the absence of any accurate way of diagnosing bone loss before the bone actually breaks, so that preventive strategies can be adopted. In the present report, a new technique for estimating in vivo bone mineral density (BMD) and mechanical reliability of heel bone has been proposed using the results of ultrasonics. This technique allows the estimation of in vivo BMD for calcaneus, vertebrae lumbales and bone fragility based on the stress analysis results. Furthermore, we examined Japanese and Korean university students including teachers on the reliability of bone applying the new method, which showed that twenty three percents of male and sixteen percents of female students were poor density of bone than the standard index recommended by WHO. Some reasons were considered such as the life styles of irregular and/or unbalance meal, and poor Ca-rich foods (e.g., milk and yogurt) as well as poor exercise.
