Abstract:Objective To develop a method for modeling spinal kinematics and dynamics of patients with adolescent idiopathic scoliosis (AIS) and verify its accuracy, so as to provide a tool for analyzing the mechanism and evaluating the effect of non-surgical orthopaedic treatment on scoliosis. Methods The skeletal and muscular parameters of the OpenSim adolescent spinal model developed by Schmid were calculated and adjusted based on imaging data to match the model with specific patients. Based on the literature data, the intervertebral stiffness was added in each vertebral joint, and modified in the scoliosis segments to make the model conform to mechanical characteristics of the vertebral joints in patients with scoliosis, and then a personalized kinematics and dynamics simulation analysis spinal model for patients with scoliosis was established. Inverse kinematics was used based on motion capture data and muscle activation was calculated using static optimization method. The calculated results were compared with imaging and electromyogram (EMG) data. Results The average angle error for the coronal plane of each vertebra was 0. 164°, which met the kinematic error requirements. The ratios of muscle activation rates for convex and concave paraspinal muscles of thoracic and lumbar segments in standing state were 0. 489 and 0. 631, respectively, which were consistent with the EMG data. Muscle activation was closer to EMG data in the modified model for intervertebral stiffness during lateral flexion than that in the unmodified model. Conclusions The model established by the method in this study meets the accuracy requirements of kinematics and muscle force.