Svensson M Y, Aldman B, Boström O, Davidsson J, Hansson H A, Lövsund P, Suneson A, Säljö A
Abteilung für Maschinen- und Fahrzeugdesign, Crash Safety Division, Chalmers Technische Universität, Göteborg.
Orthopade. 1998 Dec;27(12):820-6.
Mechanical loading of the cervical spine during car accidents often lead to a number of neck injury symptoms with the common term Whiplash Associated Disorders (WAD). Several of these symptoms could possibly be explained by injuries to the cervical spinal nerve root region. It was hypothesised that the changes in the inner volume of the cervical spinal canal during neck extension-flexion motion would cause transient pressure changes in the CNS as a result of hydro-dynamic effects, and thereby mechanically load the nerve roots and cause tissue damage. To test the hypothesis, anaesthetised pigs were exposed to experimental neck trauma in the extension, flexion and lateral flexion modes. The severity of the trauma was kept below the level where cervical fractures occur. Transient pressure pulses in the cervical spinal canal were duly recorded. Signs of cell membrane dysfunction were found in the nerve cell bodies of the cervical spinal ganglia. Ganglion injuries may explain some of the symptoms associated with soft-tissue neck injuries in car accidents. When the pig's head was pulled rearward relative to its torso to resemble a rear-end collision situation, it was found that ganglion injuries occurred very early on in the neck motion, at the stage where the motion changes from retraction to extension motion. Ganglion injuries did not occur when pigs were exposed to similar static loading of the neck. This indicates that these injuries are a result of dynamic phenomena and thereby further supports the pressure hypothesis. A Neck Injury Criterion (NIC) based on a theoretical model of the pressure effects was developed. It indicated that it was the differential horizontal acceleration and velocity between the head and the upper torso at the point of maximum neck retraction that determined the risk of ganglion injuries.
车祸期间颈椎的机械负荷通常会导致多种颈部损伤症状，统称为挥鞭样相关疾病（WAD）。其中一些症状可能是由颈神经根区域的损伤引起的。据推测，颈部屈伸运动期间颈椎管内体积的变化会由于流体动力学效应在中枢神经系统中引起瞬时压力变化，从而对神经根造成机械负荷并导致组织损伤。为了验证这一推测，对麻醉后的猪进行了伸展、屈曲和侧屈模式下的实验性颈部创伤。创伤的严重程度保持在颈椎骨折发生水平以下。适时记录了颈椎管内的瞬时压力脉冲。在颈神经节的神经细胞体中发现了细胞膜功能障碍的迹象。神经节损伤可能解释了车祸中与颈部软组织损伤相关的一些症状。当猪的头部相对于其躯干向后拉以模拟追尾碰撞情况时，发现神经节损伤在颈部运动的早期就会发生，即在运动从回缩转变为伸展运动的阶段。当猪受到类似的颈部静态负荷时，并未发生神经节损伤。这表明这些损伤是动态现象的结果，从而进一步支持了压力假说。基于压力效应理论模型开发了一种颈部损伤标准（NIC）。它表明，在颈部最大回缩点时头部与上躯干之间的水平加速度和速度差异决定了神经节损伤的风险。
