Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine, the aetiology and pathogenesis of which are poorly understood. Unfortunately, biomechanical data describing trunk muscle activation and intervertebral load, which can contribute to understanding the pathomechanics of the AIS spine, cannot be measured in vivo due to the invasiveness of the procedures. The present study provides the biomechanical characterization of the spinal loads in scoliotic subjects by exploiting musculoskeletal modelling approach, allowing for calculating biomechanical measures in an assigned posture. A spine model with articulated ribcage previously developed in AnyBody software was applied. The predicted outcomes were evaluated in the upright posture, depending on scoliosis severity and curve type, in a population of 132 scoliotic subjects with mild, moderate, and severe scoliosis. Radiographic-based three dimensional reconstruction of vertebral orientations and scaling of body segments and trunk muscle cross-section area guaranteed geometrical subject-specificity. Validation analysis supporting the application of the model was performed. Trunk muscles were found more activated in the convex side of the scoliotic curve, in agreement with reference in vivo measurements, with progressive increase with scoliosis severity. The intervertebral lateral shear was found positively correlated with the severity of the scoliosis, demonstrating that the transferred load is not a priori orthogonal to vertebral endplate in the frontal plane, and thus questioning the assumption of the ‘follower load’ approach in case of experimental or computational study on the scoliotic spine. The study opens the way for the subject-specific characterization of scoliosis in assigned loading and motion conditions.

青少年特发性脊柱侧凸（AIS）是脊柱的三维畸形，对其病因和发病机理了解甚少。不幸的是，无法在体内测量描述躯干肌肉激活和椎间负荷的生物力学数据，这些数据可能有助于理解AIS脊柱的病理力学。由于手术的侵入性。本研究通过利用肌肉骨骼建模方法提供了脊柱侧弯受试者脊柱负荷的生物力学特征，从而可以计算指定姿势下的生物力学指标。使用先前在AnyBody软件中开发的带有铰接胸腔的脊柱模型。在132名轻度，中度和重度脊柱侧弯受试者中，根据脊柱侧弯的严重程度和曲线类型，以直立姿势评估了预测的结局。椎骨方向的基于射线照相的三维重建以及身体节段和躯干肌肉横截面积的缩放保证了几何对象的特异性。进行了支持模型应用的验证分析。体内测量，随着脊柱侧弯严重程度的增加而逐渐增加。发现椎间横向剪切力与脊柱侧弯的严重程度呈正相关，表明所传递的载荷并非在额骨平面上与椎骨终板成先验正交关系，因此对实验或试验中“跟随载荷”方法的假设提出质疑。脊柱侧弯的计算研究。这项研究为指定的负荷和运动条件下脊柱侧弯的受试者特定表征开辟了道路。