Low Back Pain and the trapped nerve
I thought I'd write a newsletter about Low Back Pain (LBP) and then realised how foolish I'd been to try and fit this huge subject into the confines of one article. I expect this will be first of several dedicated to the subject! My first apology is for the dramatic title straight out of a copy of the Express. Nerves don't get trapped, any more than discs can slip or bones can crumble. These unfortunate terms have found their way into our lexicon and have been reinforced by well meaning health professionals trying to provide a vivid image of the structural faults we sometimes present with. We now know this language feeds into the negative behaviours associated with pain and just don't help!
I thought I'd kick things off by talking about the role of the nerve root in LBP. As you can see in the picture, a nerve root exits the spine between each vertebra on both sides. In the lower back these nerve roots join to form the nerves that run down the legs. Some parts do run to other parts of the abdomen and pelvis but we don't need to worry about that here. We're going to focus on how the nerve root can be injured, that said, the nerve can be injured and often is along any part of its pathway down the limb. I'll save that for another time.
Put simply, as the nerve root exits the spine, it can be squashed or irritated. The main culprits in this are the intervertebral disc and the bony edge of a facet joint. The space where a nerve roots sits isn't particularly large so anything that narrows the space could be harmful.
The nerve root becomes inflamed and highly sensitive to movement. This can become chronic and may remain even after the initial 'injury' causing compression to the nerve has resolved.
Movements where we bend backwards or to one side will close down this space even more. Similarly bending forwards or to the opposite side will open the space. This is an important principle to understand in diagnosing and treating a nerve root injury.