The test-retest reliability of cortical activation and behavioral metrics in adolescent basketball players during dual-task postural control: an fNIRS-based assessment

Abstract

Athletic performance in open-skill sports depends on the efficient integration of cognitive and motor processes under dual-task (DT) conditions. Reliable measurement of these processes is a prerequisite for assessing the functional profile of young athletes (aged 13–15) and for guiding training. This study examined the test-retest reliability (TRR) of center-of-pressure (COP) and fNIRS-derived cortical activation metrics across zero-load, low-load, and high-load conditions, assessed the reliability of N-back performance under the two dual-task conditions, and descriptively compared cortical activation patterns across load conditions in adolescent basketball players. Twenty male adolescent basketball players completed a within-subject test-retest protocol involving two visits separated by 7 days. At each visit, participants performed quiet stance alone under the zero-load condition and concurrently with auditory 0-back and 2-back tasks under the low-load and high-load conditions, respectively. Test-retest reliability was quantified using intraclass correlation coefficients (ICCs) for COP indices and fNIRS-derived t-statistics in the bilateral prefrontal cortex (PFC) and motor cortex (MC) across all three load conditions, and for N-back accuracy and reaction time under the two dual-task conditions. Most indices yielded moderate-to-excellent point estimates of reliability (ICC range: 0.609–0.984), although precision varied, with several 95% confidence intervals spanning multiple reliability categories. COP whole path length, path length per unit area, and the N-back metrics showed good-to-excellent point estimates (ICC ≥ 0.784), and fNIRS-derived t-statistics in the PFC and MC reached ICCs of up to 0.984 under high-load conditions. Within the COP domain, whole path length, circumference area, and path length per unit area constitute three non-redundant indices; mean sway velocity is a duration-normalized expression of whole path length (MSV = WPL/T) and is therefore not counted as separate reliability evidence. Grand-average maps of fNIRS-derived GLM t-statistics appeared qualitatively similar across sessions. These findings provide preliminary test-retest reliability estimates for selected multimodal neurobehavioral measures in male adolescent basketball players although reliability alone does not establish clinical utility and estimates with wide confidence intervals require confirmation in larger samples. Whether these measures can support monitoring of cognition–action coupling or inform interventions remains to be determined in future validity and responsiveness studies.