This study aimed to investigate changes occurred in the stress distribution in the growth plates (GPs) of a trunk with adolescent idiopathic scoliosis (AIS) following unilateral muscle paralysis. We hypothesized that weakening the appropriately chosen muscles on the concave side can decelerate AIS deformity progression. Muscle forces and reaction loads were estimated by an optimization-driven musculoskeletal (MS) model of adolescents with a normal- and an AIS trunk, and then applied on the finite element model of GPs of L1 through L4. Different set patterns of 95% reduction in the strength of the concave-side longissimus thoracis pars thoracic (LGPT), multifidus lumborum (MFL), and LGPT + MFL muscles were performed in the MS models. Results of this study showed that weakening of the concave-side MFL and LGPT muscles rendered a 35% correction in the symptomatic axial rotation of the AIS spine, and a reduction of about 25% in the compressive von Mises stress on the concave side of GPs, respectively, which can decelerate the deformity progression. It was observed that unilateral muscle weakening caused a compensatory activation of the rest of muscles to retain the spine stability. The intradiscal pressures and ratio between the rotations toward either side of the scoliotic spine, found here, matched well with some recent in-vivo investigations. One of the applications of the stability-based MS model of AIS spine with unilaterally weakened muscles presented in this study is to optimize the performance of the currently used braces. To fortify the presented therapeutic approach, experiments should be done on scoliotic animals.

本研究旨在调查单侧肌肉麻痹后青春期特发性脊柱侧凸（AIS）躯干生长板（GPs）应力分布的变化。我们假设，弱化凹侧的适当选择的肌肉可以减速AIS畸形发展。肌肉力和反作用力由具有正常和AIS躯干的青少年的优化驱动肌肉骨骼（MS）模型估算，然后应用于L1到L4的GP的有限元模型。在MS模型中，执行了不同的设定模式，分别降低了凹侧胸廓胸肌（LGPT），腰部多裂肌（MFL）和LGPT + MFL肌肉的强度降低95％。这项研究的结果表明，凹侧MFL和LGPT肌肉的减弱使AIS脊柱的症状性轴向旋转得到了35％的矫正，而GP凹侧的压缩von Mises应力降低了约25％。分别可以减慢畸形的进展。观察到单侧肌无力导致其余肌肉的代偿性激活，以保持脊柱稳定性。此处发现的椎间盘内压力和朝向脊柱侧凸的两侧旋转之间的比率与最近的一些情况相吻合 观察到单侧肌无力导致其余肌肉的代偿性激活，以保持脊柱稳定性。此处发现的椎间盘内压力和朝向脊柱侧凸的两侧旋转之间的比率与最近的一些情况相吻合 观察到单侧肌无力导致其余肌肉的代偿性激活，以保持脊柱稳定性。此处发现的椎间盘内压力和朝向脊柱侧凸的两侧旋转之间的比率与最近的一些情况相吻合体内调查。这项研究中提出的基于AIS脊柱稳定度MS模型的单侧肌肉减弱的应用之一是优化当前使用的牙套的性能。为了加强提出的治疗方法，应该对脊柱侧弯动物进行实验。