Evaluating cortical activity and balance performance in Alpine skiers: An fNIRS study

The study investigates the association between dynamic balance performance assessed by the modified hop balance test and cortical hemodynamics in young skiers during single-leg stance (SLS) and dual-leg stance (DLS), utilizing functional near-infrared spectroscopy (fNIRS). The study hypothesizes that SLS will enhance cortical activation than DLS due to challenging postural balance, and imbalances between right- and left-leg stances (RLS vs. LLS) will produce distinct activation patterns. The SLS and DLS were performed to understand cortical activity linked to postural control, brain areas, and lateralization's role. Differences in the hemodynamic response across experimental conditions were formally tested under the statistical framework called the functional mixed effects model, which simultaneously captures common patterns across subjects and accounts for variations in brain functional responses across subjects. Results unveiled a notable contrast (p≤0.0001) in cortical activation between SLS and DLS, with higher cortical activation during SLS, suggesting distinct neural control mechanisms. Intriguingly, distinct cortical activation patterns were observed during both stances, including various regions in the motor cortex and associated areas. No significant differences were found in cortical hemodynamics and balance performance when comparing the left-leg stance (LLS) and right-leg stance (RLS), suggesting equal stimulation of the motor cortex. Future studies comparing skiers with non-skiers might reveal different brain activity patterns between RLS and LLS, warranting further investigation into the functional role of these activations for balance improvement and targeted interventions.