Cassidy J D, Yong-Hing K, Kirkaldy-Willis W H, Wilkinson A A
Department of Orthopaedic Surgery, University Hospital, University of Saskatchewan, Saskatoon, Canada.
Spine (Phila Pa 1976). 1988 Mar;13(3):301-8. doi: 10.1097/00007632-198803000-00013.
Twenty-one bipedal rats were prepared by forelimb amputation and reared with 19 control rats. All of the bipedal rats became proficient upright walkers. There was significant anterior wedging of the lower lumbar vertebral bodies in all of the bipedal rats and four had radiographic evidence of degenerative disc disease. Five bipedal rats developed lumbosacral disc herniations, and the lumbar neural canal was significantly smaller in the bipedal population. There was no difference in radionuclide uptake between the two groups. Histochemical analysis of the psoas and multifidus muscles showed a significant shift from type I to type II fibers in the psoas and from type II to type I fibers in the multifidus in the bipedal population. These results indicate that upright posture places considerable stress on the lumbosacral spine and paravertebral muscles of the rat.
通过前肢截肢制备了21只双足大鼠，并与19只对照大鼠一起饲养。所有双足大鼠都熟练掌握了直立行走。所有双足大鼠的下腰椎椎体均有明显的前楔形改变，4只双足大鼠有椎间盘退变的影像学证据。5只双足大鼠发生了腰骶椎间盘突出，双足大鼠组的腰椎神经管明显较小。两组之间放射性核素摄取没有差异。对腰大肌和多裂肌的组织化学分析表明，双足大鼠组腰大肌中I型纤维向II型纤维有明显转变，多裂肌中II型纤维向I型纤维有明显转变。这些结果表明，直立姿势给大鼠的腰骶脊柱和椎旁肌肉带来了相当大的压力。
