Purpose
Assessing a child’s weight status is challenging when no clinical alternative to standing height measurement is available. Height from ulna length can be calculated from reliable and reproducible linear regression formula however, its effect on weight status has not been explored.
The study aimed to ascertain if Body Mass Index, determined by a calculation of height from ulna length, was reliable in identifying overweight and obese children.
Methods
In this exploratory study of 20 participants aged 2-16 years, weight status from the control, BMI from standing height was compared to BMI with height determined from ulna length, using two different methods. Method A arm extended or method B arm across chest, measured with a disposable paper measuring tape.
Results
Intra and inter reliability was high on both ulna measures with intraclass correlation (0.99). Both techniques provided similar results, respectively between mean difference in height (0.055m, P<0.001 and 0.051m, P=0.001) and BMI (-1.65kg/m2, P<0.001, and -1.51kg/m2, P<0.001). In assessment of weight status for overweight and obese, there was 100% agreement between weight status determined by standing height and weight status determined by ulna length.
Conclusions
Ulna length, measured with paper tape, provides a convenient, simple alternative method of height measurement, viable for use in assessing weight status for overweight and obesity in children. The method can be reproduced in most clinical areas and with those who have physical limitations or infectious risk where a standing height cannot be obtained. It should not be used to replace standing height when available, but can be used to reduce barriers to assessment of weight status on children, in health care facilities.
These findings prove a reliable method for assessment of weight status in children for overweight and obesity in the absence of standing height, however limited numbers suggest the need for larger studies.