Spinal Anatomy Exam III Practice

The main idea here is how the facet (zygapophysial) joints in the lumbar spine are oriented. In the lumbar region, the articular surfaces face backward (posteriorly) and toward the midline (medially). This sagittal-like orientation helps favor bending forward and backward (flexion and extension) while restricting rotation.

At the L5–S1 level, this pattern persists: the facets are directed posteriorly and medially, forming joints that align in that posterior-medial direction. This orientation underlies their role in stabilizing the lumbosacral junction while allowing flexion and extension with limited rotation.