Recording Cortical Somatosensory Responses During Cross-Country Skiing: A Feasibility and Reproducibility EEG Study

Human motor control emerges from the integrated activity of muscles, spinal circuits and cortical and subcortical brain structures. While simultaneous electroencephalographic and electromyographic recordings offer a powerful approach to assess the neuromuscular function across multiple levels, high-quality cortical measurements during dynamic whole-body movements remain technically challenging. In this study, we evaluated the feasibility and reproducibility of somatosensory evoked potentials (SEPs) recorded during V2 skate-skiing. We also examined whether cortical responses are modulated across specific sub-phases of the skiing cycle. Fourteen amateur skiers (13 males, 38 ± 8 years old) performed indoor treadmill skiing while receiving supramaximal electrical stimulation of the right tibial nerve at four timings of the gliding phase of the skiing cycle. The experimental protocol was repeated twice, 2 days apart, and it involved the simultaneous recording of wireless EEG, EMG and ski-mounted forces. Our findings indicated a robust cortical response in terms of amplitude and cortical location of the peak SEPs. SEP amplitudes demonstrated a moderate to excellent between session reproducibility (ICC > 0.83, Spearman r > 0.52) with no effect of the skiing cycle sub-phases (p > 0.05), indicating that electrically evoked SEPs primarily reflect low-level cortical processing of somatosensory afference that is minimally influenced by the ongoing motor-related cortical activity. This experimental design enables the characterization of sensorimotor integration during a whole-body dynamic task, offering new insights into the cortical mechanisms supporting skilled locomotor performance.