Anthropologists: Why is the height to femur ratio more useful?

Question

Today in lab we went over calculating the height to femur ratio and the height to head span. The instructor said that Anthropologists are more likely to use the height to femur ratio, why is this?

Answer 1

The height to femur ratio may not be more useful, but it is more consistent over a wider range of ages than the height to head span ratio is.  The is especially true for young adults and children.

You must keep in mind that the measurements are based upon assumptions and are only useful for getting a range of possible heights of the individual when a complete skeleton is not present.