# Test–Retest Reliability of Balance Parameters Obtained with a Force Platform in Individuals with Chronic Obstructive Pulmonary Disease

## TL;DR

This study shows that balance measurements using a force platform are reliable for people with COPD, supporting their use in assessing fall risk.

## Contribution

The study provides evidence of high test–retest reliability for force platform balance parameters in COPD patients.

## Key findings

- COP parameters showed good to excellent reliability (ICC = 0.82–0.95) in COPD individuals.
- Force platform measurements correlated moderately with TUG and Downton Fall Risk Scale scores.
- Low measurement error (SEM < 10%) was observed for balance parameters.

## Abstract

Background: Impaired postural balance is a common feature in individuals with chronic obstructive pulmonary disease (COPD), increasing their risk of falls. This study aimed to evaluate the test–retest reliability of force platform parameters used to assess postural balance in individuals with COPD. Methods: A test–retest reliability study was conducted with participants diagnosed with moderate to severe COPD. Each participant completed two standardized balance assessments on a force platform, separated by a seven-day interval. Center of pressure (COP) parameters—including sway area, mean velocity, and path length—were analyzed under eyes-open and eyes-closed conditions. Reliability was determined using intraclass correlation coefficients (ICC), standard error of measurement (SEM), and coefficient of variation (CV). Correlations were performed between force platform parameters, the Timed Up and Go (TUG) test, and the Downton Fall Risk Scale. Results: Twenty individuals with COPD (mean age: 67.8 ± 6.1 years; forced expiratory value in the first second: 54 ± 12% predicted) were evaluated. The COP parameters demonstrated good to excellent test–retest reliability (ICC = 0.82–0.95) across all conditions, with low measurement error (SEM < 10%). Moderate correlations were found between force platform parameters and both TUG performance (r = 0.52–0.67) and Downton scores (r = 0.48–0.61). Conclusions: Force platform measurements show high reliability for assessing postural balance in individuals with COPD. These findings support the use of objective balance assessment tools in pulmonary rehabilitation and for monitoring fall risk in this population.