X‑ray lumbar spine flexion and extension views are dynamic radiographs taken with the patient bending forward and backward to assess spinal alignment and motion. They detect abnormal vertebral translation or angulation (dynamic instability, spondylolisthesis), assess range of motion, and help evaluate degenerative or post‑traumatic changes not visible on static films. The exam is quick and uses low radiation.

A flexion-extension X‑ray captures spine images while you bend forward and backward to assess motion and alignment. It reveals abnormal vertebral movement, instability, spondylolisthesis, ligamentous injury, fusion integrity, and range-of-motion limitations from degenerative disease. It helps detect occult instability not seen on static films, guiding diagnosis and treatment decisions for cervical or lumbar spine disorders.

Normal lumbar flexion is approximately 40–60 degrees, measured as forward bending from upright. Normal lumbar extension is roughly 20–35 degrees, measured as backward bending. These values refer to combined lumbar segment motion and are measured clinically (e.g., with an inclinometer); age, sex, and activity affect ranges, and marked limitation warrants assessment by clinicians.

A dynamic flexion and extension view is a pair of X‑ray images of the spine taken while the patient bends forward (flexion) and backward (extension). They evaluate segmental motion, alignment changes, and detect instability or abnormal vertebral translation (dynamic spondylolisthesis) not seen on static films. Measurements can quantify slip or angulation between vertebrae. Indications include persistent neck/back pain, suspected instability, trauma, or post‑operative assessment.

Lumbar flexion is forward bending of the lower spine that shortens posterior tissues, increases disc pressure and stretches back muscles and ligaments. Lumbar extension is backward bending that opens anterior structures, narrows facet joints and engages spinal extensor muscles. Flexion can aggravate disc problems; extension may reduce a disc bulge for some people but can worsen spinal stenosis or facet-related pain.

The four standard lumbar spine radiographic views are: anteroposterior (AP), lateral, and the two oblique views (right and left). AP shows vertebral bodies and disc spaces; lateral demonstrates vertebral alignment, disc height, and the spinal canal; oblique views visualize the facet joints and pars interarticularis for spondylolysis or facet arthropathy, and to detect fractures or degenerative change.