Whiplash injury causes neck pain, stiffness, headache, shoulder pain, and neurological symptoms, with women more sensitive than men. Symptoms occur consistently across rear, frontal, and lateral impacts. Research focuses on nerve injury in spinal ganglia as the injury site, as this explains why long term whiplash symptoms include neurological symptoms independent of crash direction. The Neck Injury Criterion (NIC) measures injury using the formula NIC = 0.2Δa + Δv², where Δa is acceleration difference and Δv is velocity difference. Whiplash motion causes rapid volume changes inside the vertebral canal, with epidural blood volume pumped to compensate. Animal experiments using pressure sensors show pressure changes in skull and spine at different vertebral levels during whiplash events.