I wrenched my low back and my neck in a car accident. The back pain went away after a couple of weeks but the neck pain keeps on. I guess I'm a little surprised because I usually get better fast after any injury. Why is the neck taking so long?

Pain in the cervical spine (neck) after car accidents is often some type of whiplash injury. The formal term given this problem is whiplash-associated disorder (WAD).

Based on insurance claims, WAD is very common. More than half of all car accident victims file with some type of neck injury. Up to one-third of these people end up with chronic neck pain.

Many studies have been done trying to find the cause of persistent pain after WAD. The mechanisms of low back pain have been compared with neck pain linked to WAD. It appears that the facet joints in both areas of the spine may be the source of the pain.

Animal studies show there may be a difference in how pain signals are interpreted and transmitted between these two areas. It may be that the joints in the cervical spine have more units ready to send the pain message. It's also possible that these units called nociceptors have a lower threshold. This means they fire sooner than later.

There's much we still don't know about what signals are sent to trigger pain messages or even how to stop them. Current research is focused on whether the joint is being pinched, pressed, strained, or stretched. Finding the source of pain generation will help us develop better ways to turn off the signals and thereby prevent excess pain messages from getting through.