Lindbeck L
J Biomech Eng. 1985 Aug;107(3):281-5. doi: 10.1115/1.3138554.
An upright, muscle-relaxed human spine, suffering from a mild functional scoliosis, caused by a small difference in leg length, is modeled as an anisotropic, elastic beam. The lower end of the beam is built-in in a fixed body, i.e., the laterally tilted pelvis. The upper end is rigidly attached to a rigid body, i.e., the supported upper part of the trunk, which is supposed to move freely in the frontal plane. It is shown that the characteristic scoliotic curvature of the spine, observed on an X-ray picture, can be reproduced by means of buckling analysis of the beam model, using realistic values of geometric and loading parameters and a properly chosen bending stiffness, which is found to be in reasonable agreement with earlier experimental findings. The analysis also shows that the muscle-relaxed upright equilibrium position of the spine is mechanically unstable.
一个患有轻度功能性脊柱侧弯的直立、肌肉放松的人体脊柱，由腿长的微小差异引起，被建模为一个各向异性的弹性梁。梁的下端固定在一个固定体中，即横向倾斜的骨盆。上端刚性连接到一个刚体上，即躯干的支撑上部，假定其在额平面内自由移动。结果表明，通过梁模型的屈曲分析，利用几何和载荷参数的实际值以及适当选择的弯曲刚度，可以再现X射线照片上观察到的脊柱特征性侧弯曲率，发现该弯曲刚度与早期实验结果合理吻合。分析还表明，脊柱肌肉放松的直立平衡位置在力学上是不稳定的。
