Is arm span an accurate measure of height to predict pulmonary function parameters?

Area of Science:

• Pulmonary Medicine
• Anthropometry

Background:

• Pulmonary function tests (PFTs) rely on predicted normal values based on body height.
• Accurate measurement of body height is often challenging in clinical settings.
• Arm span is an alternative for estimating height, but its relationship with height varies across demographics.

Purpose of the Study:

• To determine the relationship between body height and arm span in a Persian population.
• To evaluate the accuracy of PFT predictions using height estimated from arm span versus direct arm span measurements.
• To establish regression equations for height estimation from arm span, considering age and sex.

Main Methods:

• Collected data on body height and arm span from 754 males and 708 females (ages 7-82) with normal stature.
• Developed linear regression equations for the body-height/arm-span ratio, analyzing subgroups by age (≤20 and >20 years) and sex.
• Compared spirometric parameters predicted using measured height versus height estimated from arm span.

Main Results:

• Significant sex and age differences were observed in the arm-span/height ratio.
• Spirometric parameters derived from arm span alone were statistically different and overestimated compared to those from measured height.
• Most PFT parameters, particularly vital capacity, showed no significant statistical difference when predicted by measured height versus height estimated from arm span.

Conclusions:

• Height estimated from arm span is a more reliable predictor of pulmonary function parameters than arm span alone.
• This method offers improved accuracy for PFT interpretation when direct height measurement is not feasible.