Department of Anatomy and Structural Biology, University of Otago, Dunedin, New Zealand.
Spine (Phila Pa 1976). 2011 Jul 15;36(16):E1053-61. doi: 10.1097/BRS.0b013e3181f79629.
STUDY DESIGN. A qualitative and semiquantitative study of the morphology of the human thoracolumbar transversospinal (TSP) muscles. OBJECTIVE. To further define the functional morphology of the thoracolumbar TSP muscles. SUMMARY OF BACKGROUND DATA. The TSP muscle group plays an important role in vertebral function but few studies have rigorously investigated their morphology throughout the thoracolumbar region and details on the location of motor endplates (MEPs) and fiber types are sparse. METHODS. Thoracolumbar TSP muscles were examined by microdissection in five cadavers (seven sides). MEPs were identified using acetylcholinesterase histochemistry in muscles between T5 and S4 unilaterally in two cadavers. The relative proportions of type I and type II skeletal muscle fibers were determined using immunohistochemistry on whole cross sections of every TSP muscle from one side of one cadaver (T5-S4). RESULTS.TSP morphology was homogeneous and consistent throughout the thoracolumbar region. Notable differences to standard descriptions included: (1) consistent attachments between muscles; (2) no discrete cleavage planes between muscles; and (3) attachment sites over the sacrum and to lumbar zygapophysial joints. Previously undescribed small muscles were found attaching to the medial sacrum. All TSP muscles were multipennate, with fibers arranged in parallel having one MEP per muscle fiber. Muscles were highly aerobic (mean proportion of type I fibers 89%), with the proportion of type I fibers decreasing caudally. A significantly greater proportion of type I fibers were found in the midthoracic compared to the low lumbar regions. CONCLUSION. The complex morphology of the TSP muscles indicates that they would be better classified as spinotransverse muscles. They are multipennate, highly aerobic, with fibers organized in parallel, an arrangement lending itself to "fine-tuning" of vertebral movements. Understanding their morphology has implications for investigation, treatment, motor control, and biomechanics.
研究设计。对人类胸腰椎横突间（TSP）肌肉形态的定性和半定量研究。目的。进一步定义胸腰椎 TSP 肌肉的功能形态。背景资料总结。TSP 肌肉群在椎体功能中起着重要作用，但很少有研究严格调查它们在胸腰椎区域的形态，关于运动终板（MEP）的位置和纤维类型的细节也很少。方法。在五具尸体（七侧）中通过显微解剖检查胸腰椎 TSP 肌肉。在两具尸体的单侧 T5 至 S4 之间的肌肉中使用乙酰胆碱酯酶组织化学鉴定 MEP。使用免疫组织化学在一具尸体一侧的每个 TSP 肌肉的整个横切面上确定 I 型和 II 型骨骼肌纤维的相对比例（T5-S4）。结果。TSP 形态在胸腰椎区域内是均匀和一致的。与标准描述的明显区别包括：（1）肌肉之间的一致附着；（2）肌肉之间没有明显的分离平面；（3）附着在骶骨和腰椎关节突关节上。在以前未描述的小肌肉附着在骶骨内侧。所有 TSP 肌肉都是多羽状的，纤维平行排列，每条肌肉纤维有一个 MEP。肌肉高度有氧（I 型纤维的平均比例为 89%），尾部的 I 型纤维比例降低。中胸段的 I 型纤维比例明显高于低腰段。结论。TSP 肌肉的复杂形态表明它们最好被归类为脊柱间肌肉。它们是多羽状的，高度有氧的，纤维平行排列，这种排列方式有利于“微调”椎体运动。了解它们的形态对研究、治疗、运动控制和生物力学都有影响。
