Biomechanical analysis of scoliosis correction under the influence of muscular and external forces

(1) Background: External force orthopedics and the strengthening of paraspinal muscles through exercise are common orthopedic methods for adolescent scoliosis, yet the synergetic mechanism of the two in orthopedic correction remains unclear. (2) Methods: A three-dimensional finite element model of the scoliotic spine was established to accurately simulate the mechanical properties of tissues such as the spine, intervertebral discs, and ribs. By applying external forces in different directions to the scoliosis model, the orthopedic effects of these forces on scoliosis were analyzed. Furthermore, considering the influence of muscular forces on scoliosis, the role of muscle contraction in the correction of scoliosis was simulated. (3) Results: The applied external forces significantly reduced both the Cobb angle and the vertebral rotation angle of the scoliotic spine. Specifically, the Cobb angle was corrected from 25° to 14°, achieving a scoliosis correction rate of 44%, while the apical vertebral rotation angle was corrected from 10.8° to 8.59°, resulting in a rotation correction rate of 20.46%. Furthermore, with the addition of muscular forces, the scoliosis correction rate increased further to 75.08%, and the apical vertebral rotation correction rate reached 11.39%; (4) Conclusions: Simultaneous exercise of paraspinal muscles while wearing an orthosis to improve muscular imbalance, can further reduce the Cobb angle and enhance the orthopedic effect.