There are times when we don’t react appropriately to other people. Either we misread the situation, or lack the skill to respond more tactfully. There is an element of judgement involved in our reactions, and that includes our reactions to injuries.
As with our reactions to other situations, the repair process is not always appropriate because it depends on our interpretation of the injury. One purpose of the natural movement development of a child is to more accurately understand/react to physical injury. This is mostly a kinesthetic skill, but it is empowering to have a basic intellectual understanding as well.
Phase I: A-specific reaction
Being calm is an effect of feeling safe. For that reason, most of the sights, sounds, and even sensations from your body are ignored because you have already determined that their threat level is low. The mechanism involves several filters in your brain which are more closed when one is calm. As you can see, the space between the black lines is small, and mild sounds like those of a clock, or the sensation from your skin against your clothes get absorbed by the brain before making their way to your awareness in the cortex. Only intense sounds or sensations will penetrate the filters.
A sudden jerk, the screeching sound of breaks, or any harsh stimulation suddenly penetrates into the cortex, initiating a strong sense of awareness, which we generally term arousal. During this time, one is physically very strong. Most alarms are false, and as soon as we determine that the harsh sound its harmless, whether we are right or wrong, the arousal passes, and there is no need to further recruit the immune system because injury is unlikely.
The purpose of the arousal is clearly to avoid serious injury, and keep you alive should serious injury occur.
Let’s assume for our purposes that an injury does occur in the foot only. At the moment we realize that the foot is hurt but there is no threat to our life, we move to Phase II in which the the protective reactions are contained to the injured area as opposed to the whole body.
Phase II: Specific Reaction
While an arousal is a stage of whole body protection due to a threat to the whole body, Phase II is a protective state of only the damaged part, in our scenario the foot. Before an injury in the foot crosses the filter into the cortex, it must first cross a similar filter in the portion of the spinal cord that corresponds to the foot. The same filter mechanism described below the cortex could be described in the corresponding region of the spinal cord.
The receptors in the foot detect the injury, inform the spinal cord, and make it more reactive in very much the same way the brain becomes more reactive after hearing a loud sound. Pro inflammatory chemicals are actually sent from the spinal cord to the injured tissues. The inflammation is simply a cleaning of the same damaged debris that alerted the signal for help. These chemicals actually stimulate the same pain fibers even more, so at this point your foot is hurting even if you don’t move; a necessary protective mechanism considering the vulnerability of the tissue at this stage of recovery.
If at any point during recover, if an event important enough occurs where you absolutely have to run, your brain will be able to block out the pain, but during this phase it would be very difficult. In the image, the blue line represents your ability to move the injured foot. The red line coming up to the brain represents pain, which competes, and in this case, overpowers the blue line.
During this phase, however, the tissue is so vulnerable it would be impossible to will yourself past it for very long. This forces you not to move or put weight on the foot while the damaged tissue is carried away. Once that happens, the chemical pain is no longer present, and the edge should come off the pain.
Phase III: Mesh Phase
Normally after a few days phase II is complete; the injury is clean, and new tissue is being laid there. As the new scar is being laid, the body compares information coming from the new scar with our movement to determine the appropriate volume of scar to produce.
Mesh Test Passed:
The spinal cord detects when normal tension is applied to the healing area without causing damage, and the caution meters in the spinal cord and brain decrease. If this type of sensation (#1) dominates what the spinal cord is receiving, it knows that more force can be handled, strength will increase (#1) , and the inflammation reflex described previously is inhibited (#2). Pain will diminish with time, and stage IV will begin.
Mesh Test Failed: When actual damage occurs to the young scar (#1 pain signal), the corresponding area of the spinal cord is more likely to transmit pain input to the brain (#2), activating the corresponding area in the cortex. At the exact moment the awareness occurs, the output from the brain (#3) no longer blocks the inflammation reflex, and the strength of release of pro inflammatory chemicals (#4) increases. The recovery process will begin again, this time with more scar based on a more defensive spinal core/brain.
Warning Pain: It is fairly obvious why anything threatening would be cause for alarm, while anything soothing would have the opposite effect. But thankfully any threat is dealt with before actual damage, which means your body has to have a way of sensing injury ahead of time. Understanding this warning system is probably the key to understanding the relationship between ones psyche and recovery from injury.
Our tissues, especially young scar, possess pain receptors which fire a little before actual damage takes place. Suppose you are lying on the couch and your four year old starts to jump on your outstretched arm. The defensive reactions will kick in very easily, even before he breaks your arm. On the other hand, suppose you are running on the beach. The same arm might be moving behind you even faster, but the defensive reactions are not activated. This is due to the repetitive nature of the movement and the lower arousal of the brain.
Another way to put it is as follows. When arousal is high, warning signals are interpreted by the spinal cord as threatening. When arousal is low, warning signals are interpreted as non threatening, and even stimulate endorphins which strongly block pain. The psyche largely determines whether or not to progress to stage IV or go back to stage I.
State IV: Memory Reset
Walking normally without pain indicates you have completed the goals of stage III. Your tissues are strong enough to walk, and your caution meter is adjusted accordingly. In order to complete the recovery process, the new tissues have to be able to withstand full force.
A degree of hypersensitivity persists even after graduating from stage III, precisely because it is not known yet if the tissues are able to withstand the force of running and jumping. A couple tests are performed to determine whether or not this hypersensitivity, which is really a bias towards self-protection, is justified.
The first test is the actual forceful movement, which is a forceful output (blue line) away from the cortex. The forceful output closes the filter, which will close further with each forceful movement unless a pain signal is received. Movement closes the filter, and nociception (tissue damage signal) opens it. If you pass the test you are on your way to wiping the pain memory.
But your tissues also have to withstand more mild forces for longer periods of time. Now let’s suppose you run or play soccer for an hour. A large volume of intense but non-injury input from your leg reaches the filter. But since the filter is closed due to passing the prior test, the brain knows it can ignore most of this information. In fact, after 15 minutes of ignoring the information, the brain finds it easier to drip endorphins down into the spinal cord, blocking all that input before it even comes up. These endorphins powerfully block pain memories, and their production continues for hours/days.
At this point, you have passed all the stress tests. There in no reason to restart the inflammation, or even have a sensitive spot where the injury was.