Regional variation in the mechanical properties of the vertebral column during lateral bending in Morone saxatilis
Regional variation in the mechanical properties of the vertebral column during lateral bending in Morone saxatilis
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DOI：
10.1098/rsif.2012.0153
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发表时间：
2012-10-07
影响因子：
3.9
通讯作者：
Brainerd, E. L.
中科院分区：
文献类型：
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作者：
Nowroozi, B. N.;Brainerd, E. L.
与哺乳动物的盘状椎间关节 (IVJ) 不同，鱼类的 IVJ 是双锥体结构，充满液体，被认为在游泳时充当静压铰链关节。然而，目前尚不清楚哪些 IVJ 结构在鱼类对力的机械抵抗力方面起主导作用，以及这些组织的变化是否可能影响脊柱沿其长度的功能。在这里，我们测量了条纹鲈 (Morone saxatilis) 的 IVJ 的动态机械行为。在侧向弯曲过程中，尾部和颈部区域的角刚度明显低于腹部区域。中性区定义为弯曲力矩小于 0.001 Nm 时的运动范围 (ROM)，相对于腹部 IVJ，尾部的中性区更长。所有区域的滞后均为 30-40%，表明 IVJ 可能在游泳过程中的能量耗散中发挥作用。切割垂直隔膜没有统计学上显着的影响，但切割封装组织会导致角刚度急剧下降，ROM 和滞后大幅增加。我们得出的结论是，条纹鲈从头到尾的刚度降低，ROM 增加，并且封装组织在沿脊柱长度的机械变化中发挥着重要作用。
Unlike mammalian, disc-shaped intervertebral joints (IVJs), the IVJs in fishes are biconid structures, filled with fluid and thought to act as hydrostatic hinge joints during swimming. However, it remains unclear which IVJ structures are dominant in mechanical resistance to forces in fishes, and whether variation in these tissues might impact the function of the vertebral column along its length. Here, we measured the dynamic mechanical behaviour of IVJs from striped bass, Morone saxatilis. During lateral bending, angular stiffness was significantly lower in the caudal and cervical regions, relative to the abdominal region. The neutral zone, defined as the range of motion (ROM) at bending moments less than 0.001 Nm, was longer in the caudal relative to the abdominal IVJs. Hysteresis was 30-40% in all regions, suggesting that IVJs may play a role in energy dissipation during swimming. Cutting the vertical septum had no statistically significant effect, but cutting the encapsulating tissues caused a sharp decline in angular stiffness and a substantial increase in ROM and hysteresis. We conclude that stiffness decreases and ROM increases from cranial to caudal in striped bass, and that the encapsulating tissues play a prominent role in mechanical variation along the length of the vertebral column.