Whiplash is a neck injury due to forceful, rapid back-and-forth movement of the neck. Whiplash often occurs during a rear-end auto accident, but the injury can also result from a sports accident, physical abuse or other trauma. Common signs and symptoms of whiplash include neck pain, stiffness and headaches. Most people with whiplash get better within a few weeks by following a treatment plan that includes physical therapy and exercise. However, some people have chronic neck pain and other long-lasting complications.