Most of us tend to think of pain as beginning at a tissue level. For example, if you sliced your finger on a knife while cutting vegetables in the kitchen. The obvious cause is the cut, but the less understood part is why we feel the pain. The pain we feel in this instance may actually be caused by the brain as a survival mechanism. Sensory structures in the skin, nociceptors, send a signal to the brain that is processed. The brain identifies signals that are dangerous and responds by sending a pain signal. This causes us to react and protect the injured area. So using our example when the knife slices the finger, the brain receives a signal identifies a threat and sends a pain signal causing us to put down the knife, pull our hand away and treat the injury. This protects us from further injury, and forces us to treat the injury effectively so that it may heal.
Individuals react to these injuries differently which is why pain is not always an accurate indicator of injury or damage. Our reactions are based on a number of factors, attitude, past experiences, sensory cues, and knowledge for example. Combined with the signals received from the nociceptors the brain uses these factors to determine the level of danger, when determining its response. If you think of your own past experiences how many times have you noticed a bruise somewhere on your body and had no idea how it got there? In fact a study done examining pain at the time of injury found that 37% of people examined in emergency care felt no pain at the time of the injury. Some reported pain within an hour and for some it took nine hours or more. These people were alert, rational, not in shock and not intoxicated.[I]
The Gate Control Theory
The Gate Control Theory, introduced in the 1960’s was the first theory that explained how pain perception is far more complex then simply the degree of injury equaling the degree of pain. Essentially the theory explains that there are “gates” at the spinal cord level that determine which nerve signals reach the brain. [ii] The Gate Control Theory of Pain theorizes that there are two types of nerve fibers in the body, small nerve fibers (pain receptors) and large nerve fibers (non-pain receptors) that attach to a synapse on a cell which transmits the signal to the brain. The theory is that only one signal can make it through the synapse at a time. So imagine playing a game of musical chairs with two people and one chair. Whoever sits on the chair first wins, it is the same in the Gate Control Theory. When only the large fibers (ones that don’t cause pain) are stimulated it prevents signals of pain from getting to the brain. To use an example, you bang your elbow on the corner of a table. This activates the small fibers which send a pain signal to the brain. After banging the elbow you rub it with your hand to try to sooth it. This stimulates the large fibers, blocking the pain signal from reaching the brain, reducing the amount of pain in your elbow.
As described earlier there are a number of factors that determine how the “gates” will handle the pain or “danger” signal. For example if the pain is acute the danger signal will reach the brain quickly. This is a survival mechanism meant to protect the body. For example if you touch a hot pan, the signal will reach the brain quickly telling you to pull the hand away. However, in the case of chronic pain, the signal is often slow. The brain will process these messages differently and respond accordingly. Outside factors will also affect the strength of the minds response. For example, past experiences, mental state (depression, anger, stress etc), negative thoughts and external activities (is the body currently in a threatening situation), all will affect the brains response.
As you can see pain is a very individualized process. Two people may have identical injuries but due to other factors may have completely different pain responses. It is important that when dealing with both acute and chronic pain that an integrated treatment program individualized to suite each individual be created. This is one of the reasons why Pure Body Balance provides several different modalities for treatment and integrates them for the patients benefit. By utilizing the various education and skill sets of different types of practitioners, the patient sees the best result.
The Gate Control Theory is relevant in treatment for a number of reasons. But an often overlooked aspect is the importance of movement. Often the first reaction we have to pain is to try to rest. For example low back pain, a person dealing with chronic low back pain may restrict their activities and frequently avoid physical activity in an effort to allow the injury to heal. However, as the Gate Control Theory shows, movement is an important part of any treatment plan to relieve chronic pain. When we stop moving our muscles tighten, we lose strength, we gain weight from being inactive and the pain signals intensify because the “gates” are wide open. When we are moving, this can be as simple as a brisk walk, sensory information closes the “gates” reducing pain allowing us to prevent loss of strength and combating weight gain. Movement also enhances blood flow to the tissues, which brings cleans out waste and brings much needed nutrients and oxygen to the tissue to stimulate repair of the tissue.
Want to learn more? Contact us and we would be happy to answer any of your questions!
To your health,
Keegan Marshall CPT, CES
[i] (1) http://www.ncbi.nlm.nih.gov/pubmed/7145438