Test-retest reliability of postural control measures in healthy secondary school pupils: insights from the MOVE12 pilot study.

Abstract

Introduction: Postural control is an essential part of human movement. Measurements of center of pressure displacements by force platform are considered the gold standard for assessing postural control. However, the test-retest reliability of these measurements in field-based conditions is unclear.

Methods: This study aimed to investigate the test-retest reliability of center of pressure measures under field-based conditions, and assess the impact of height, weight, and body mass index (BMI) on test-retest reliability. The study sample comprised 215 upper secondary school pupils (114 girls) aged 16-17 years, all drawn from the control group of a larger intervention study. There was a 12-week interval between the initial test and the retest. Measurements of center of pressure displacements was assessed during a bipedal eyes closed and a unipedal eyes open condition. Interclass correlation coefficients (ICCs) with 95% confidence intervals were calculated for six distinct measures in both conditions. Correlations between the change in postural control and height, weight, and BMI were assessed as well.

Results: Trace length exhibited the best test-retest reliability in both conditions, achieving moderate to good reliability in the bipedal eyes closed condition (ICC = 0.73, 95% CI = 0.66-0.78). Test-retest reliability was higher for all measures in the bipedal eyes closed (ICC's = 0.53-0.73) compared to unipedal eyes open condition, and some of these measures approached zero reliability (ICC's = 0.03-0.48). Among body characteristics, only height was significantly correlated with test-retest changes in postural control (r = 0.16, p < 0.05) and only for two of the measures.

Discussion: This study underscores the necessity of careful selection of postural control measures and thorough assessments in field-based research to achieve acceptable test-retest reliability.