Corpulence index

The Corpulence Index (CI) or Ponderal Index (PI) is a measure of leanness of a person[1] calculated as a relationship between mass and height.[2] It was first proposed in 1921 as the "Corpulence Index" by Rohrer and hence also known as Rohrer's Index.[3] 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.[4]

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

For a baby, it is calculated as

\mathrm{CI} = \frac{birth weight}{Crown-heel-length^3}[5]

with mass in kg (kilograms) and height in m (meters), 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] The normal values for infants are about twice as high as for adults, which is the result of their relatively short legs. It does not need to be adjusted for age after adolescence.[4] It has also been shown to have a lower false positive rate in athletes.[9]

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 corresponding to "normal"
BMI in a 180 cm tall person
\text{CI}=\frac{mass}{height^3}[8] kilograms metres 10.3 to 13.9, 24 for 12-month-old infant[7] ~12 for those 12-year-old or older.[4]
\text{CI}=1000\frac{mass}{height^3}[7] grams centimetres 2.4 for 12-month-old infant
\text{CI}=1000\times\frac{\sqrt[3]{mass}}{height}[2] kilograms centimetres 21.75 to 24.0[10]
\text{CI}=100\times\frac{\sqrt[3]{mass}}{height}[11] kilograms centimetres 2.175 to 2.4
\text{CI}=\frac{height}{\sqrt[3]{mass}}[1] pounds inches 12.49 to 13.92

Significance

See also

References

  1. 1 2 Foods and Nutrition Encyclopedia, Audrey H. Ensminger, Marion Eugene Ensminger. p. 1645
  2. 1 2 EXSS 323: LAB 1 - BIOMECHANICS TOOLS: Computers, Algebra and Trig Oregon State University
  3. ↑ http://www.wisegeek.com/what-is-the-ponderal-index.htm
  4. 1 2 3 4 Babar, Sultan (March 2015). "Evaluating the Performance of 4 Indices in Determining Adiposity". Clinical Journal of Sports Medicine (Lippincott Williams & Wilkins)) 25 (2): 183. Retrieved August 2015.
  5. ↑ Fayyaz, Jabeen (June 2005). "Ponderal Index". Journal of Pakistan Medical Association.
  6. ↑ Lawrence F. Ditmier: New Developments in Obesity Research. Nova Science Publishers, Hauppauge, New York 2006, ISBN 1-60021-296-4
  7. 1 2 3 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. 1 2 ACC/SCN NUTRITION POLICY PAPER No. 19 - Glossary by Lindsay H. Allen and Stuart R. Gillespie
  9. ↑ Babar, Sultan (March 2016). "The Use of Adiposity Indices for Wide Receivers From 2015 NFL Combine". Clinical Journal of Sports Medicine (Lippincott Williams & Wilkins) 2) 26 (2): e23. Retrieved April 2016.
  10. ↑ The source quoted (Oregon State University) states that typical healthy PI values range between 20 and 25.
  11. ↑ Medical Dictionary University of Newcastle upon Tyne
  12. ↑ Khoury, MJ; Berg, CJ; Calle, EE (September 1990). "The ponderal index in term newborn siblings.". American Journal of Epidemiology 132 (3): 576–83. PMID 2389761.

External links

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