This is pain originating from the facet (intervertebral) joints—small joints that connect adjacent vertebrae and ensure the stability and mobility of the spine. The facet joints in the cervical or lumbar spine are most commonly affected. The pain is usually localized and worsens when straightening the spine, twisting, or standing for long periods. In the cervical region, it may radiate to the back of the head or shoulder; in the lumbar region, to the buttocks or thigh. Causes include degenerative changes, overuse, and trauma. Diagnostic facet joint blocks may be performed to confirm the diagnosis.