A cervical spine extension and flexion view are lateral X‑rays taken while the patient bends the neck backward (extension) and forward (flexion). They assess dynamic alignment and segmental instability, detect occult listhesis or ligamentous injury, and evaluate fusion integrity or causes of chronic neck pain and radicular symptoms. These views are avoided if an acute unstable injury is suspected.

The lateral view is the single most important cervical spine x‑ray. It best demonstrates vertebral body alignment, intervertebral disc spaces, facet joints, and prevertebral soft tissues, making it most sensitive for fractures or subluxation. For complete evaluation it’s usually combined with AP and open‑mouth odontoid (C1–C2) views; oblique views may be added to assess the foramina.

Flexion-extension X‑rays are dynamic spine films, especially of the cervical and lumbar regions, taken with the patient bending forward and backward to assess vertebral movement and alignment. They detect abnormal translation or angulation (instability), spondylolisthesis, ligamentous injury, failure of spinal fusion, and motion-related narrowing of foramina or canal, revealing instability not seen on static X‑rays.

Dynamic flexion and extension views are X‑ray images taken while a patient bends forward (flexion) and backward (extension) to evaluate spinal alignment and motion. They assess instability, ligamentous injury, abnormal vertebral translation (spondylolisthesis), and dynamic cord or nerve compression not visible on static films. These views are commonly used for cervical or lumbar assessment after trauma or with neck/back pain and neurologic symptoms.

Flexion decreases a joint angle — bending a limb so bones move closer (e.g., elbow or knee bend, bringing the hand toward the shoulder or the heel toward the buttock). Extension increases the angle — straightening or moving a limb away (e.g., straightening the elbow or knee). For the spine, flexion is forward bending and extension is backward arching. Think closer means flexion; farther or straighter means extension.

The three standard cervical spine views are: anteroposterior (AP) — shows vertebral bodies and alignment; lateral — best for overall alignment, vertebral heights, and prevertebral soft tissues (important in trauma); and open‑mouth (odontoid) — visualizes C1–C2 and the odontoid process to assess atlantoaxial alignment and odontoid fractures.