- IJ
117: Determining stature from bone length
So what if you find a skeleton in cave where it appears much larger than usual? How do you determine the height of the individual? Firstly you need to determine if the bone belongs to a male or a female. That's where you start.
In the early days of first finding the cave back in 2016 we found a formulae that seemed quite simple. A femur is 26.74% of a persons height based on an average between men and women. However, that would only be used if a bone was found with no other skeleton parts present. It turns out that is nowhere near accurate enough and we now have the formulae that are dependent on sex, and origin. DNA testing will determine which formulae we use and initially we'll just use the average of the averages. Confused? So are we!
There is a proper formulae and there are three measurements variables to use depending on what part of the bone you measure (especially in the case of the thigh bone). Race also allows for +/- percentages. However, if the race is unknown (as it will be in our case), once would just take the 'average' rather than the 'maximum' to ensure we aren't seen as professionally 'inflating' - after all we are not politicians! However, as bones from anywhere near Asia are calculated at 2.5% less than other measurements. That may equate to 5.54 cm or only 2.18 inches
We have covered this a long time ago, but here it is in another format.
Take the measurement of the top of the Fovea Capitus to the bottom of the Medial Condyle...
That is measurement A in the picture below and the most common tool to do this is in the second picture. Of course, in the cave we do not want to touch anything for fear of DNA contamination so we will be using a vertical rod measure for a reasonably accurate assessment.
First you determine the sex of the individual by observation of the pelvic bones. Then you measure the femur as above. A = the maximum length. If a male it would mean the femur (as an average +/-) would be 25.1% of overall height. If the femur was 74cm the person would be 8'0". If a female, a 74cm femur = 7'7".
However, we want the median measurement which is called the 'femur bicondylar length'. This is somewhere between measurement A & B and is where the Lateral and Medial Condyle are flush and the measurement is from that to the top of the Fovea Capitus. That might reduce the measurement to suggest the height of the individual is 7'10". We are not ones to produce a probable 'maximum' just for effect, we want the true average. Experts can later provide accurate figures.
There are other methods of measurement as well and I'm sure many will suggest they are more accurate ways to measure, but the key is to produce that first provocative photo of a femur with a tape measure beside it so people can make up their own mind. And be sure the height will only be the first thing of many differences to be revealed...
With the first photo we release, if a male (and one can tell by pelvis shape amoung other things), we are hoping to show at least one femur at least 75cm which will average out at the median measurement of 8'0". If we took the maximum probable maximum bone length it would be 8'5". Regardless that it would be 37% taller (at the median measurement) than the average American male!
