Proportionality constants describe the average ratio of a given body segment length to stature. The ratios used here are from Drillis and Contini (1966) and are among the most-used (see figure to the left). Their use can be problematic, however, since segment ratios of any individual are not likely to be “average”. In other words, the ratios for a given segment vary widely across individuals within a given population. Also, while a measure like “shoulder height” correlates well with stature (R2 = 0.93), other measures, such as “shoulder breadth” (R2 = 0.15) do not. As a result, this is a helpful tool for exploring relationships, but should not be used for real design.
The R2 and RMSE are reported for each segment by tapping on the indicated value. These values come from a regression on the ANSUR data.
For a more detailed discussion of the strengths and weaknesses of proportionality constants, see Fromuth and Parkinson (2008), “Predicting 5th and 95th percentile anthropometric segment lengths from population stature” by visiting dfhv.org.