Snijders C J, Hoek van Dijke G A, Roosch E R
Department of Biomedical Physics and Technology, Erasmus University, Rotterdam, The Netherlands.
J Biomech. 1991;24(9):783-92. doi: 10.1016/0021-9290(91)90303-5.
To gain a better understanding of the forces working on the cervical spine, a spatial biomechanical computer model was developed. The first part of our research was concerned with the development of a kinematic model to establish the axes of rotation and the mutual position of the head and vertebrae with regard to flexion, extension, lateroflexion and torsion. The next step was the introduction of lines of action of muscle forces and an external load, created by gravity and accelerations in different directions, working on the centre of gravity of the head and possibly a helmet. Although the results of our calculations should be interpreted cautiously in the present stage of our research, some conclusions can be drawn with respect to different head positions. During flexion muscle forces and joint reaction forces increase, except the force between the odontoid and the ligamentum transversum atlantis. This force shows a minimum during moderate flexion. The joint reaction forces on the levels C0-C1, C1-C2, and C7-T1 reach minimum values during extension, each in different stages of extension. Axial rotation less than 35 degrees does not need great muscle forces, axial rotation further than 35 degrees causes muscle forces and joint reaction forces to increase fast. While performing, lateral flexion muscle forces and joint reaction forces must increase rapidly to balance the head. We obtained some indications that the order of magnitude of the calculated forces is correct.
为了更好地理解作用于颈椎的力，我们开发了一个空间生物力学计算机模型。我们研究的第一部分关注运动学模型的开发，以确定屈伸、侧屈和扭转时头部与椎体的旋转轴及相互位置。下一步是引入肌肉力的作用线以及由重力和不同方向加速度产生的作用于头部重心（可能还有头盔）的外部载荷。尽管在我们研究的现阶段，对计算结果应谨慎解读，但关于不同头部位置仍可得出一些结论。在屈曲过程中，除了齿突与寰椎横韧带之间的力外，肌肉力和关节反作用力会增加。该力在适度屈曲时显示出最小值。C0 - C1、C1 - C2和C7 - T1水平的关节反作用力在伸展过程中达到最小值，且分别处于不同的伸展阶段。轴向旋转小于35度时不需要很大的肌肉力，轴向旋转超过35度会使肌肉力和关节反作用力快速增加。在进行侧屈时，肌肉力和关节反作用力必须迅速增加以平衡头部。我们得到了一些迹象表明计算力的数量级是正确的。
