Whiplash - How does it happen? Whiplash occurs most commonly from riding in a vehicle that is struck from behind or that collides with another object. When the head is suddenly jerked back and forth beyond its normal limits, the muscles and ligaments that support the spine and head can be overstretched or torn. The soft, pulpy discs between spinal bones can bulge, tear or rupture. Vertebrae can be forced out of their normal position, reducing range of motion. The spinal cord