ORIENTATION AND MECHANICAL ANALYSIS OF THE LUMBAR ZYGAPOPHYSEAL JOINTS / 解剖学报

ABSTRACT

The stereoscopic orientation of the lumbar zygapophyseal joints and the stability triangle of the motion segments were studied on 56 sets of adult lumbosacral skeletons. The orientation of the lumbar zygapophyseal joints changed gradually from about sagittal plane in upper segment to about coronal in lower. The gravity center of the stability triangle of the motion segments moved backward from upper to ower progressively. Therefore, the stability of lumbar spine decreases and the mobility increases successively from upper downward.