Effects of Tibialis Anterior Muscle Activity on the Cervical Rotation Range According to the Perspective of the Spiral Fascia Line

Purpose: This study examined the relationship between the tibialis anterior muscle activity and cervical rotation range of motion (ROM) along the spiral myofascial line, which contributes to rotational stability and postural control.Although previous research has suggested that the fascia is a continuous and dynamic structure affecting the musculoskeletal function, direct evidence of active fascial contraction influencing remote joint mobility remains limited.Methods: Twenty healthy adults (11 males and nine females; mean age 30.7 5.0 years) with right foot dominance voluntarily participated in this study.The tibialis anterior activity was recorded using surface electromyography under standardized electrode placement, and the cervical rotation ROM was assessed with a smartphone-based goniometer.Independent t-tests were used to compare the muscle activity between dominant and non-dominant sides, while paired t-tests examined the differences in cervical rotation ROM with and without tibialis anterior activation.Results: The tibialis anterior activity was significantly higher on the dominant side (81.24 8.22%MVIC) compared to the non-dominant side (76.52 8.91%MVIC, p< 0.05).No baseline difference in the cervical rotation ROM was found between the right and left sides.On the other hand, ipsilateral cervical rotation ROM increased significantly during active contraction of the tibialis anterior (right: 64.98 10.1671.576.82; left: 64.35 8.3773.856.71, p< 0.05).Conclusion: These findings show that tibialis anterior contraction enhances ipsilateral cervical rotation ROM along the spiral line.The results highlight the clinical relevance of myofascial continuity, suggesting the potential applications of fascial chain activation in rehabilitation strategies for patients with restricted cervical mobility.