The exact source of acute low back pain is often difficult to identify. In fact, there are numerous possible pain producers including muscles, soft connective tissue, ligaments, joint capsules and cartilage, and blood vessels. These tissues may be pulled, strained, stretched or sprained. Additionally, annular tears (small tears that occur in the outer layer of the intervertebral disc) can initiate severe pain. Even if the actual tissue damage is minor, and likely to repair quickly, the pain experienced may be quite severe.
No matter which tissue is initially irritated, a cascade of events occurs which contributes to the pain experience. Numerous chemical substances are released in response to tissue irritation. These substances “stimulate” the surrounding pain sensitive nerve fibers, resulting in the sensation of pain. Some of these chemicals trigger the process of inflammation, or swelling, which also contributes to pain. The chemicals associated with this inflammatory process feed back more signals which perpetuate the process of swelling. The inflammation attributable to this cycle of events may persist for days to weeks.
Muscular tension (spasm) in the surrounding tissues may occur resulting in a “ trunk shift” (the body tilts to one side more than the other) due to muscular imbalance. Additionally, a relative inhibition or lack of the usual blood supply to the affected area may occur so that nutrients and oxygen are not optimally delivered and removal of irritating byproducts of inflammation is impaired.
No comments:
Post a Comment