ROCKMIND: Multimodal neurophysiological assessment of grip force control and fatigue in sport climbing

Abstract Introduction. Sport climbing performance critically depends on sustaining submaximal grip forces under fatigue while maintaining precise force control. From a neurophysiological perspective, this process requires coordinated recruitment of motor units in the forearm musculature and effective corticospinal control originating in motor cortical areas. Despite the importance of these mechanisms for force regulation and fatigue, the neurophysiology of sustained gripping in climbing remains insufficiently understood. Hangboard training represents a central component of climbing-specific training. These exercises involve repeated or sustained isometric contractions using body weight and induce controlled loading of the forearm musculature. Importantly, hangboard tasks provide a highly standardized and experimentally tractable paradigm, making them well-suited for investigating neuromuscular and neural mechanisms of grip force control. Methods. The ROCKMIND project introduces a multimodal experimental framework combining high-density surface electromyography (HD-sEMG) of the forearm musculature, electroencephalography (EEG), and force measurements during standardized hangboard tasks to investigate peripheral and central mechanisms of force control and fatigue. Ninety participants will be stratified according to the International Rock Climbing Research Association (IRCRA) reporting scale into non-climbers, recreational climbers (IRCRA 10-17 men, 10-14 women), and elite climbers (IRCRA >24 men, >21 women). Participants will perform controlled isometric grip contractions (finger flexion) on the hangboard at 20%, 35%, and 50% of their maximal voluntary contraction. Results. Preliminary measurements in one participant using HD-sEMG of the forearm musculature show the feasibility of the hangboard setup and reflect clear fatigue-related changes in electromyographic activity during sustained contractions. EEG acquisition and corticomuscular coherence analyses will be performed as part of the ongoing study. Conclusion. The preliminary findings support the feasibility of the proposed methodology for investigating grip force control and fatigue in sport climbing. By examining how grip force is maintained and how control strategies change as a function of fatigue and climbing expertise, the project aims to identify neurophysiological markers relevant for performance assessment and training monitoring.