less than 127 lbs.) and low body mass index (BMI, / 2, e.g. Height and weight, as well as sex and ethnicity, are both components of the input for DXA and FRAX. Substantial loss of height suggests the possibility of prevalent vertebral fractures and the need for further evaluation with spine imaging ( Table 63.3). The hinged height measurement device on a typical office scale is usually not sufficiently accurate to be clinically useful in detecting changes in height. Measure height with a calibrated wall-mounted stadiometer or metal ruler compare with historical maximum height to calculate historical height loss (HHL) and compare with previous stadiometer-measured height, if available, to calculate prospective height loss (PHL). Michael Lewiecki, in Osteoporosis (Fourth Edition), 2013 Vital Signs