A lumbar flexion and extension X‑ray are dynamic radiographs taken while you bend forward (flexion) and backward (extension) to assess lower spine alignment and motion. They reveal abnormal vertebral movement, instability, spondylolisthesis, or failed fusion that static images may miss. The quick, usually standing exam uses low-level radiation and helps guide diagnosis and treatment of mechanical back pain.

An X‑ray of the lumbosacral (LS) spine in lateral flexion is a radiographic view taken while the patient bends sideways to assess spinal alignment and segmental mobility. It helps detect abnormal motion, instability, spondylolisthesis, and degenerative changes between vertebrae. The exam is quick, noninvasive, and uses low-dose radiation; findings guide diagnosis and treatment planning.

Normal lumbar spine flexion is approximately 40–60° and extension about 20–35° in adults. Values vary with age, soft-tissue flexibility and measurement technique. Clinically, total forward bending includes hip motion, so isolated lumbar contribution may be less. Persistent or progressive symptoms merit physiotherapy or imaging.

Lumbar spine flexion is the forward‑bending motion that decreases the angle between the trunk and pelvis, occurring primarily at the lumbar vertebrae. It produces anterior compression of vertebral bodies and discs while stretching posterior ligaments and extensor muscles. Typical active range is about 40–60 degrees. Excessive or repetitive flexion raises disc load and can contribute to low back pain or disc injury.

The primary clinical test for lumbar flexion is the Schober test (commonly performed as the Modified Schober or Modified-Modified Schober). It assesses lumbar spine forward flexion by marking lumbar landmarks, measuring the distance while upright and again at maximal forward bend; a larger increase indicates normal flexion, while a smaller change suggests reduced lumbar mobility.

Flexion decreases the angle between bones at a joint—bending movements (e.g., elbow flexion brings the forearm toward the upper arm; spinal flexion is bending forward). Extension increases the angle—straightening or bending backward (e.g., elbow extension straightens the arm; spinal extension arches the back). Flexor muscles cause flexion; extensors cause extension.