The orientation of the lumbar zygapophyseal joints changed gradually from about sagittal plane in upper segment to about coronal in lower.
腰椎间关节的方位自上而下，由近矢状位逐渐过渡为近冠状位；
2
The shape of the articular surface of the cervical zygapophyseal joint could be divide into circular-type, ellipse-type which is the most one in each segment, and irregular-type.