Finite element analysis of neck sports injury based on a whole cervical spine model with muscles.

Cervical atlantoaxial subluxation injuries, often resulting from high-intensity external forces or improper posture during high-speed, rotational sports, pose significant risks to athletes' health and careers. This study aims to investigate the biomechanical effects of atlantoaxial subluxation on the cervical spine. Models representing Model 1 (healthy bone model), Model 2 (healthy muscle model), and atlantoaxial subluxation diseased model were developed using CT and MRI data. A 30 N gravitational force and a 1.5 Nm torque were applied to the C0 node. The study simulated changes in range of motion (ROM), disc stress, and muscle stress under six motion states-flexion-extension, lateral flexion, and axial rotation-to evaluate the post-injury movement limitations of the cervical spine. The validity and consistency of this study with cadaver data from the literature were verified through range of motion (ROM) comparison and Bland-Altman analysis. Compared to the healthy model, the diseased model showed a reduction in ROM, with a 10°-30° decrease in C0-C1 ROM across all six movements. The distribution of stress shifted from the bones to the damaged atlantoaxial joint and muscles, while the stress on the intervertebral discs decreased. This study, through the establishment of a finite element model of the cervical spine, reveals the biomechanical effects of atlantoaxial subluxation on the cervical spine, including reduced ROM, altered stress distribution, and increased muscle load. The findings provide a theoretical basis for the prevention of sports injuries, the development of rehabilitation programs, and personalized treatments, emphasizing the importance of muscle recovery and proper management of movement loads. Future work will further validate and expand the application by integrating clinical data.