Whiplash is a common injury in motor vehicle accidents, particularly in rear-end collisions.  The Mayo Clinic defines whiplash as a “neck injury that can occur…when your head suddenly moves backward and then forward … These extreme motions push your neck muscles and ligaments beyond their normal range of motion.” The sudden neck movement can be serious and cause trauma to the spine and head as well.
While bumpers generally absorb energy, certain add-ons to the rear bumpers of cars interfere with the bumpers’ ability to absorb the energy during an accident.  In a paper published in 2000, it was shown  cars with a towing hitch that were involved in a rear end collision increased the chance of whiplash by 22%.
It may be a good idea to remove towing hitches or other add-ons from the rear of your vehicle while not towing.   If you have been in an accident, be sure to seek treatment immediately.