Which spinal ligament is responsible for resisting extension?

The anterior longitudinal ligament is indeed responsible for resisting extension of the spine. This ligament runs along the front of the vertebral bodies, extending from the sacrum to the base of the skull. Its primary function is to maintain stability during movements that would otherwise promote excessive extension, thereby preventing injury to the spinal column.

When the spine extends, the anterior longitudinal ligament becomes taut and limits the range of this motion, helping to protect the intervertebral discs and support spinal alignment. This role is crucial for maintaining proper biomechanical function during activities that involve bending backward or extreme posture changes.

It's essential to recognize that the other ligaments listed have different functions or effects. The posterior longitudinal ligament is primarily involved in resisting flexion, the interspinous ligament provides stability during flexion and extension motions but is not primarily tasked with resisting extension, and the ligamentum flavum assists in preventing excessive flexion and helps maintain the normal curvature of the spine.