Neuromuscular Responses of the Cranio-Cervico-Mandibular System During Professional "110th Targa Florio" Rally Competitions: An Electromyographic Study in Real-World Racing Conditions.

Background/

Objectives

Professional motorsport imposes substantial biomechanical, postural, and cognitive demands that require continuous neuromuscular adaptations to ensure vehicle control and head stabilization during competition. Although the cranio-cervico-mandibular system may contribute to these adaptive responses, its role in rally performance remains poorly understood. This study aimed to investigate neuromuscular adaptations of the cranio-cervico-mandibular system in professional rally drivers under real-world racing conditions and to explore the relationship between masticatory muscle activity, cervical involvement, and jaw-clenching behavior.

Methods

Twenty professional drivers and co-drivers participating in the 110th Targa Florio Rally were enrolled in the study. All participants underwent static surface electromyography (sEMG) assessment using the Teethan® system to evaluate the masseter, anterior temporalis, and sternocleidomastoid muscles. During competition, dynamic masseter muscle activity was monitored using the dia-BRUXO® system. Neuromuscular balance parameters, cervical involvement, masseter muscle activity, and clenching and grinding episodes were analyzed.

Results

Participants showed a generally preserved baseline stomatognathic neuromuscular balance, with greater inter-individual variability in cervical involvement. During competition, clenching episodes were significantly more frequent than grinding episodes (p < 0.001). A moderate positive correlation was observed between Cervical Load and the number of clenching episodes (rho = 0.570, p = 0.011). No significant correlations were found between stomatognathic functional indices and dynamic bruxism-related parameters.

Conclusions

Professional rally drivers exhibited increased masticatory muscle activity during competition, predominantly characterized by jaw clenching. The association observed between Cervical Load and clenching episodes suggests a statistical concomitance between cervical and masticatory muscle recruitment, which reaches high levels in these elite athletes but requires further longitudinal research to confirm a directional functional interaction in cranio-cervical stabilization during high-demand driving tasks.