Assuring Pediatric Nutrition in the Community

FREQUENTLY USED GUIDELINES:
Assessing Nutritional Status - Estimations of Stature

Arm span measurements
Knee height measurements
Crown-rump and sitting height measurements

What if I cannot make an accurate measurement of a child’s height?
When the length or height of a child cannot be accurately measured, several options are available to estimate stature, including arm span, knee height, crown-rump, and sitting height measurements. These are only approximations of stature, but can provide information, especially when used longitudinally. For a few measurements, methods for extrapolating stature have been published. Estimations of stature can be plotted on growth charts, but it is important that a notation of the estimation method be made on the chart.

What are arm span measurements?
Arm span measurements are helpful in estimating the stature of some children whose lower bodies are affected; e.g., because of paralysis or contractures. There is generally a 1:1 relationship between stature and arm length. An anthropometer (stainless steel rod with one moveable sleeve) is used to measure arm span. The child extends his/her arms at right angles to his/her body, and sits or stands with a straight back. The distance between his/her extended right and left middle fingers is measured across the back.

This measurement is not appropriate for children under 5 or 6 years of age, because limbs and total body length do not grow at equal rates during this time. It is also not appropriate for children who are not able to extend their arms or sit with a straight back; e.g., children who have scoliosis or upper body contractures.

Jarzem PF and Gledhill RB. Predicting height from arm measurements. Journal of Pediatric Orthopaedics. 1993; 13: 761-5.

What are knee height measurements?
Knee height is the distance from the top of the patella to the bottom of the foot. Equations for estimating stature from knee height have been published for children over 6 years of age. These measurements can be plotted on growth charts, and trends can be monitored. In general, growth should follow the general pattern of the growth chart.

Chumlea WC et al. Prediction of stature from knee height for black and white adults and children with application to mobility-impaired or handicapped persons. J Am Diet Assoc.1994;94:1385.

Stevenson RD. Use of segmental measures to estimate stature in children with cerebral palsy. Archives of Pediatric and Adolescent Medicine. 1995; 149(6): 658-62.

What are crown-rump and sitting height measurements?
Crown-rump and sitting height measurements can be used as substitutes for stature for infants and children whose lower bodies are affected (e.g., by contractures) or shorter than expected. These measurements cannot be used to estimate a child’s stature, but changes can be plotted on growth charts to assess growth.

Crown-rump length is measured using a length board with a fixed headboard and moveable footboard. The length between the crown of the child’s head and buttocks is measured.

Sitting height is measured with a stadiometer attached to a measuring board. The child sits on a box of known height; this height is subtracted from the measurement obtained.

Hamill et al. Body weight, stature, and sitting height: White and Negro youths. Vital Health Statistics. 1973; 11(126).

Smith D. Growth and its disorders. Major Problems in Clinical Pediatrics. Volume 15. WB Saunders Co. 1977.