|The Pain Cycle|
The body's pain cycle is an interesting one, but is also fundamental to understanding what is occurring in our own bodies. When tissue gets damaged, inflammation occurs. The increase of blood flow to the damaged area brings in the various cells and materials for repair. In addition, the swelling caused by the inflammation creates more pressure in the area, which can stimulate the pressure sensitive nerves sending signals to the brain. The signals are usually interpreted as pain. This is all very normal, and in many cases the situation stops there since the area gets repaired and the inflammation goes away.
In some cases, the pain sensation is so strong that the surrounding tissue is told to protect the damaged area from any further damage. The surrounding tissue protects the damaged area by clamping down and creating a wall preventing movement in the area of the damaged tissue. In the short term, this muscle splinting is a helpful action. In a longer term scenario, splinting becomes a problem since the area that is clamped down to protect ends up getting irritated and inflamed by being protective for so long. So the protecting area starts the pain cycle anew, and the irritated inflamed and injured area continues to grow. This is called a positive feedback loop, where the process continues to grow. As the injured area and the associated pain continues, more of the nervous system becomes involved and the pain can spread further out in the body. Usually pain will spread from the local tissue into neighboring tissue, then further along the limb or trunk. Eventually it spreads to the opposite side of the body, and then further up and down the body. In some of the most severe cases, the pain has spread out through the whole body and limits the person's daily activities.
The way to prevent the pain cycle from growing or continuing is to provide outside stimulus aimed at reducing the originally injured and restricted tissue, which reduces inflammation and also pain.