Common mechanical causes of low back pain include disc herniations. Most clinicians acknowledge that if a tissue is damaged, there is a reasonable probability that it will produce pain. In the 'old days', we used to believe that a disc herniation would pinch a nerve and lead to pain. But as we realized that true nerve impingement (although it does occur) was less common than previously believed, the low back community began to look outward.
When there is tissue damage, lots of noxious chemicals are released. These chemicals are generally used to communicate with different components of your body that are responsible for healing and repair. But it is becoming clear that these chemicals (broadly termed 'cytokines'), can be problematic if they persist.
This paper describes the production of inflammatory cytokines by damaged tissues. As they activate immune cells and the brain, the brain responds by promoting further release of these inflammatory triggers. These authors describe the way that these signals cross the blood brain barrier and influence our perception of pain through a "cascade of altered neural activity." This can promote the efficiency of the "pain pathways" to the brain and lead to persistent pain.
So far, so good. But another question remains; is there anything else that leads to the production of these inflammatory cytokines? In other words, can another event, apart from tissue damage at the low back, produce these nasty chemicals. If so, then this would have the potential to make relatively minor tissue damage... a REALLY BIG DEAL. The answer is a resounding yes. Before we detail some of these components, picture this.
Have you ever caught a friend at just the wrong moment? Perhaps you made an innocent comment, "I like your other shoes more than the ones you're wearing." And all of a sudden, your friend explodes! It may have been a minor statement, but if she just got fired from her job, broke up with her boyfriend, had her credit cards stolen and her car is making funny noises, then your minor statement was the "straw that broke the camel's back" in an already traumatic day.
If your brain is already compromised by a poor diet and lifestyle, then even a minor stimulus will lead to a major symptomatic eruption. Remember, the brain not only maintains normal body mechanics, but also perceives pain. Alteration in its function can heighten sensitivity and generate vicious cycles of pain.