Evaluating Cortical Activity and Balance Performance in Alpine Skiers
Using Single-Leg Stance and Modified Hop Balance Test
Abstract
The study investigates the impact on cortical activation during
Single-leg Stance (SLS) and Dual-leg Stance (DLS) and its connection to
skier balance performance, utilizing functional nearinfrared
spectroscopy (fNIRS). In this experiment, nine young skiers
participated, performing both SLS and DLS on challenging surfaces while
being monitored with fNIRS. We introduced an alpinespecific balance test
called the Modified Hop Balance Test (MHBT), designed to assess the
balance proficiency of skierâ\euro™s ability to control the upper
bodyâ\euro™s vertical orientation during SLS. We employed a
statistical model based on a functional mixed-effects framework to
analyze hemodynamic response changes across various conditions. The
results from the MHBT with open eyes (tests 1 and 2) revealed variations
in stability between the left and right foot when moving forward,
compared to lateral movements with the same foot (tests 5 and 7).
Interestingly, skiers exhibited slightly better overall scores in
lateral movements compared to straight-line ones, indicating their
proficiency in maintaining stability during sideways skiing. SLS
exhibited significantly higher cortical activation than DLS, with no
significant difference observed between left and right-leg stances. It
appears that tasks demanding greater motor control or higher complexity
lead to increased cortical activation. For future research, a
longitudinal study is needed to observe how training and corresponding
neuromuscular efforts influence cortical activation over time.
Furthermore, we hypothesize that as athletes improve their balance
skills, the level of cortical activity will become more optimized and
similar in both SLS and DLS conditions. Therefore, considering
lateralized patterns of cortical activity could be valuable when
interpreting postural deficiencies in cases of SLS.