Facet joints are the bony protrusions at the back of the spine which join the vertebrae together. They are the joints that make your back flexible and allow you to bend and twist.
The joints are lined with cartilage and lubricated by a substance called synovial fluid. When healthy, the bones move freely over each other without grinding.
Nerves pass through the joints from the spinal cord to on their way to the rest of the body.
Degenerative changes in the discs and subsequent thinning of discs can cause pressure on the facet joints, affecting how the joints line up. This added pressure causes wear and tear which eventually destroys the cartilage and fluid in the joint and causes the soft tissue surrounding the joint to swell.
As a result of this damage, the bones rub together. When this happens, the body tries to heal itself by building new bone which results in the formation of bone spurs, growths which protrude from the bone and can press on the nerves which pass through the joint.
There is an added risk that these bone spurs continue to grow and narrow the spinal canal.
When suffering from facet joint syndrome, movements such as bending backwards or twisting sideways towards the affected joint will cause pain.
Standing for long periods may make it worse and anything which takes the weight off the joint such as sitting or lying down can ease the pain.