Ponderal-Index
The ponderal index, also called Rohrer index, is a measure for the evaluation of body weight ( physically correct body mass ) in relation to body size, similar to the body mass index. In contrast to this, however, the mass is m divided by the cube of height l, ie based on a ( fictitious ) volume rather than on a surface:
With in kg and m.
Values 11 to 14 kg/m3 correspond Normalgewichtigkeit. In contrast to the BMI of the ponderal index provides loud Ditmier even for very small and very large body sizes a valid statement. The reason for this is that the index meets the conditions of a dimensionless measure of the similarity theory for the influence of body size. The 1908 (cited in ) proposed index is itself suitable for the assessment of birth weight and the mass of small children, even if the normal values will roughly double, as an expression of the relatively small leg lengths. The normal value at 12 -month infants is 24 kg/m3.
In infants and young children, the PI will, however, often calculated using the following formula:
With in g and cm.
The numerical values are then pik but by a factor of 10 smaller than PI. It should therefore uniformly the first formula can be used for all body sizes on the SI base units meter ( m) kilogram ( kg ) of the International System of Units is based.