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为研究马尾神经对牵拉损伤的耐受极限及其在不同强度损伤下的变化过程，作者设计了动物马尾神经牵拉损伤的模型。手术将家犬Ｌ_（３、４）椎骨间连接的韧带及椎间盘彻底松解，并在Ｌ_２、Ｌ_３、Ｌ_４及Ｌ_５椎体中各穿针一枚，连接外固定器。用外固定器撑大Ｌ_（３、４），椎骨间隙，于不同的牵拉强度和时间，检测动物马尾诱发电位、下肢疼痛反射和肌力。实验发现，急性２ｃｍ牵拉损伤可引起马尾诱发电位波形降低和畸变；立即去除牵拉损伤力，马尾诱发电位波形迅速恢复正常，次日动物肌力和疼痛反射恢复正常。但持久的２ｃｍ牵拉损伤，则造成持续的马尾诱发电位降低、畸变和运动、痛觉障碍。将牵拉损伤长度增加到３ｃｍ、４ｃｍ，则见到马尾诱发电位波形进一步降低、畸变，最后消失。由此可见椎骨间分离移位，可造成椎管内神经根牵拉损伤，使马尾诱发电位波幅降低或消失，并产生运动、痛觉障碍。轻度牵拉损伤引起的神经功能障碍是可以恢复的。但严重的牵拉损伤则引起不可逆转的神经功能障碍或丧失。
In order to study the tolerance of the cauda equina to the traction injury and its changes under different intensities of injury, the authors designed a model of the cauda equina nerve traction injury. The ligaments and intervertebral discs of L_ (3,4) vertebrae of dogs were completely released by surgery and one needle was inserted in L_2, L_3, L_4 and L_5 vertebrae to connect the external fixator. The external fixator was used to support the L_ (3,4) and vertebral space. The ponies evoked potentials, lower extremity pain reflexes and muscle strength were measured under different tightening strength and time. The experimental results showed that acute 2 cm stretch injury caused the decrease and distortion of the waveform of caudal evoked potentials. Immediately removed the extensional injury force, the caudal evoked potential waveform returned to normal quickly, and the strength and pain reflex of animals on the following day returned to normal. However, persistent 2 cm stretch injury results in persistent poncho evoked potentials, distortions and motility, and pain disorders. Will stretch the injury length increased to 3cm, 4cm, then see the pony evoked potential waveform to further reduce the distortion, and finally disappear. This shows that the displacement of intervertebral separation can cause spinal nerve root traction injury, the cauda equina induced potential amplitude decreases or disappears, and exercise, pain disorders. Nerve dysfunction caused by mild stretch injury is recoverable. However, severe traction injuries cause irreversible neurological dysfunction or loss.