Harrison D D, Janik T J, Troyanovich S J, Harrison D E, Colloca C J
Department of Mathematical Sciences, University of Alabama, Huntsville 35899, USA.
J Manipulative Physiol Ther. 1997 May;20(4):246-56.
To evaluate the accuracy of anatomical assumptions made to derive a geometrical, ideal, normal model of the upright, static, sagittal cervical spine, to make comparisons with other spinal models and to discuss the implications of a normal cervical model.
Anatomical assumptions were made based on observations to assist in the development of a computerized geometrical model of the ideal upright, static, sagittal cervical spine. These assumptions address the magnitudes of the contribution made by the vertebral bodies and intervertebral discs to the overall magnitude and geometric shape of the cervical lordosis.
(a) Data were collected from 400 lordotic lateral cervical radiographs and compared with the predictions of a geometric normal cervical lordotic model. Angels of intersecting tangent lines, drawn at posterior vertebral body margins, were measured at each disc space and between C2 and C7. Height-to-length ratios and an anterior weight-bearing distance were measured. (b) LITERATURE REVIEWs were obtained through Medline and Chirolars.
(a) Modeling: the 400 sample subjects varied from the geometric model by approximately 5%. Subgroup averages, from partitioning the C2-C7 angle into 5 degrees intervals, were less than 8% in error to model predictions. (b)
lordosis is the normal configuration for the cervical spine and many chiropractic empirical models are similar.
The anatomical assumptions used to derive our normal geometric model of the cervical lordosis seem to be supported by the average values and literature reviewed. Two typical geometric configurations of the cervical spine were identified as a normal circular lordotic arc of 34 degrees and an ideal normal of 42 degrees. LITERATURE REVIEWed establishes cervical lordosis as a desirable clinical outcome of care.
评估为得出直立、静态、矢状位颈椎的几何理想正常模型所做解剖学假设的准确性，与其他脊柱模型进行比较，并探讨正常颈椎模型的意义。
基于观察结果做出解剖学假设，以辅助开发理想直立、静态、矢状位颈椎的计算机化几何模型。这些假设涉及椎体和椎间盘对颈椎前凸的总体大小和几何形状的贡献程度。
(a) 从400张颈椎前凸侧位X线片收集数据，并与几何正常颈椎前凸模型的预测结果进行比较。在每个椎间盘间隙以及C2和C7之间，测量在椎体后缘绘制的相交切线的角度。测量高度与长度之比以及前负重距离。(b) 通过医学文献数据库（Medline）和脊椎按摩疗法文献数据库（Chirolars）获取文献综述。
(a) 建模：400名样本受试者与几何模型的差异约为5%。将C2-C7角度划分为5度间隔的亚组平均值与模型预测的误差小于8%。(b) 文献综述：前凸是颈椎的正常形态，许多脊椎按摩疗法经验模型与之相似。
用于推导我们颈椎前凸正常几何模型的解剖学假设似乎得到了平均值和文献综述的支持。确定了颈椎的两种典型几何构型，一种是34度的正常圆形前凸弧，另一种是42度的理想正常构型。文献综述表明颈椎前凸是理想的临床护理结果。
