McGill S M, Jones K, Bennett G, Bishop P J
Occupational Biomechanics Laboratory, Department of Kinesiology, University of Waterloo, Ontario, Canada.
Clin Biomech (Bristol). 1994 May;9(3):193-8. doi: 10.1016/0268-0033(94)90021-3.
The passive bending stiffness, tolerable bending moment levels, and elastic energy storage capabilities of the cervical spine were evaluated in 40 male and 19 female volunteer subjects from a university student population, about the flexion, extension, and lateral bending axes. Bending moments were applied to the neck while subjects lay on a frictionless jig and simultaneous angular displacements of the skull relative to the rib cage were recorded. Myoelectric signals from the sternocleidomastoid and splenius capitis muscles were amplified over audio speakers to train subjects to relax their musculature. Tolerable levels of bending moments were quite low (less than 10 N m on average for all conditions) given the very large magnitude of bending moment applied to the neck estimated from impact models. Subjects tolerated greater moment and elastic energy storage in the cervical passive tissues during flexion than in both extension and in lateral bending. In addition males were able to tolerate larger applied moments, were stiffer, and stored more energy than females in all loading conditions. The data derived from this study of loading at very slow rates provide a lower limit for bending moments and for cervical spine stiffness, and yield a first approximation to dynamic bending stiffness values that may be included in models of the cervical spine.
在40名男性和19名女性大学生志愿者中，评估了颈椎关于屈伸和侧弯轴的被动弯曲刚度、可承受弯矩水平以及弹性能量储存能力。让受试者躺在无摩擦夹具上，向颈部施加弯矩，并记录颅骨相对于胸廓的同步角位移。来自胸锁乳突肌和头夹肌的肌电信号通过扬声器放大，以训练受试者放松其肌肉组织。考虑到根据撞击模型估计施加在颈部的弯矩幅度非常大，可承受的弯矩水平相当低（所有条件下平均小于10 N·m）。与伸展和侧弯相比，受试者在颈椎被动组织屈曲时能承受更大的弯矩和弹性能量储存。此外，在所有加载条件下，男性比女性能够承受更大的施加弯矩，更僵硬，并且储存更多能量。这项以非常缓慢的加载速率进行的研究得出的数据提供了弯矩和颈椎刚度的下限，并给出了动态弯曲刚度值的初步近似值，这些值可纳入颈椎模型中。
