# Corpulence index

The Corpulence Index (CI) or Ponderal Index (PI) is a measure of leanness (corpulence) of a person[1] calculated as a relationship between mass and height.[2] It was first proposed in 1921 as the "Corpulence measure" by Swiss physician Fritz Rohrer[3] and hence is also known as Rohrer's Index.[4] It is similar to the body mass index, but the mass is normalized with the third power of body height rather than the second power.[5]

${\displaystyle \mathrm {CI} ={\frac {mass}{height^{3}}}}$

with ${\displaystyle mass}$ in kilograms and ${\displaystyle height}$ in metres, giving a measure with the same dimensions as density. The corpulence index yields valid results even for very short and very tall persons.[6] Because of this property, it is most commonly used in pediatrics.[7][8] (For a baby, one can take crown-heel length for the height.[9]) The normal values for infants are about twice as high as for adults, which is the result of their relatively short legs.[citation needed] It does not need to be adjusted for age after adolescence.[5] It has also been shown to have a lower false positive rate in athletes.[10]

The corpulence index is variously defined (the first definition should be preferred due to the use of SI-units kg and m) as follows:

Formula Units for mass
(body weight)
Units for height
(or length)
Values considered normal or typical
for a 12-month-old infant beyond infancy
${\displaystyle {\text{CI}}={\frac {mass}{height^{3}}}}$[8] kilograms metres 24[7] 12[5]
${\displaystyle {\text{CI}}=1000{\frac {mass}{height^{3}}}}$[7] grams centimetres (same values as above)
${\displaystyle {\text{CI}}={\frac {height}{\sqrt[{3}]{mass}}}}$[1][11] pounds inches 12.49 to 13.92

## References

1. ^ a b Foods and Nutrition Encyclopedia, Audrey H. Ensminger, Marion Eugene Ensminger. p. 1645
2. ^ EXSS 323: LAB 1 - BIOMECHANICS TOOLS: Computers, Algebra and Trig Oregon State University
3. ^ F. Rohrer (1921). "Der Index der Körperfülle als Maß des Ernährungszustandes". Münchner Med. Wschr. 68: 580–582.
4. ^ http://www.wisegeek.com/what-is-the-ponderal-index.htm
5. ^ a b c d Babar, Sultan (March 2015). "Evaluating the Performance of 4 Indices in Determining Adiposity". Clinical Journal of Sport Medicine. Lippincott Williams & Wilkins). 25 (2): 183. Retrieved August 2015. Check date values in: |access-date= (help)
6. ^ Lawrence F. Ditmier: New Developments in Obesity Research. Nova Science Publishers, Hauppauge, New York 2006, ISBN 1-60021-296-4[page needed]
7. ^ a b c Davies, D. P. (1980). "Size at birth and growth in the first year of life of babies who are overweight and underweight at birth". Proceedings of the Nutrition Society. 39 (1): 25–33. doi:10.1079/PNS19800005. PMID 6988835.
8. ^ a b ACC/SCN NUTRITION POLICY PAPER No. 19 - Glossary Archived 2007-08-20 at the Wayback Machine by Lindsay H. Allen and Stuart R. Gillespie
9. ^ Fayyaz, Jabeen (June 2005). "Ponderal Index". Journal of Pakistan Medical Association.
10. ^ Babar, Sultan (March 2016). "The Use of Adiposity Indices for Wide Receivers From 2015 NFL Combine". Clinical Journal of Sport Medicine. Lippincott Williams & Wilkins) 2. 26 (2): e23. Retrieved April 2016. Check date values in: |access-date= (help)
11. ^ https://captaincalculator.com/health/weight/ponderal-index-calculator/
12. ^ Khoury, MJ; Berg, CJ; Calle, EE (September 1990). "The ponderal index in term newborn siblings". American Journal of Epidemiology. 132 (3): 576–83. doi:10.1093/oxfordjournals.aje.a115694. PMID 2389761.