The joints in the spinal column are located posterior to the vertebral body (on the backside). Facet joints help the spine to bend, twist, and extend in different directions. Although these joints enable movement, they also restrict excessive movement such as hyperextension and hyperflexion (i.e. whiplash).
Each vertebra has two sets of facet joints. The superior articular facet faces upward and works like a hinge with the inferior articular facet (below).
Like other joints in the body, each facet joint is surrounded by a capsule of connective tissue and produces synovial fluid to nourish and lubricate the joint. The surfaces of the joint are coated with cartilage that helps each joint to move (articulate) smoothly.