The lumbar facet joints are small, paired joints located at the back of each vertebra in the lower spine. They help guide and limit movement in the lumbar spine, particularly in extension and rotation, while also contributing to the overall stability of the spinal column. Each facet joint is lined with cartilage and surrounded by a capsule, which allows for smooth movement and provides a source of sensory input to the nervous system. These joints can become sensitised due to various factors such