Chansigaud J P, Criscuolo J L, Kamina P
Laboratoire d'Anatomie, Faculté de Médecine, Poitiers.
Bull Assoc Anat (Nancy). 1986 Sep;70(210):39-45.
It is conventional saying that the fetal rachis shows only one ventral concavity. An echographic study allowed to observe in utero the rachis of more than a hundred live fetuses. The radius of this curvature gradually increases according to the development, revealed by the disappearance of the cervical curvature under the influence of the weight of the head and the uterine constraints. The sagittal curvatures of the vertebral column explains mans adaptability to the erected position. The authors think that the conventional conception, in which ontogenetic development is comparable with phylogenetic development, needs to be reconsidered: the cervical curvature is a prime curvature setting the evolutionist question about the origins of the rachidian curvatures.
传统观点认为胎儿脊柱仅呈现一个腹侧凹陷。一项超声研究得以在子宫内观察一百多个活胎儿的脊柱。这种弯曲的半径会随着发育逐渐增加，这在头部重量和子宫限制的影响下，颈椎弯曲消失得以体现。脊柱的矢状弯曲解释了人类对直立姿势的适应性。作者认为，那种将个体发育与系统发育相类比的传统观念需要重新审视：颈椎弯曲是一个原发性弯曲，引发了关于脊柱弯曲起源的进化论问题。
