A great (and quite entertaining) video on the actual process of how pain works by Lorimer Moseley, from the 2011 TedX Adelaide conference - "Why Things Hurt"
My favourite quote from this is:
A key conceptual shift that we think is really important is that you can understand that pain is the end result, pain is an output of the brain, designed to protect you - it’s not something that comes from your tissues.
In other words, pain is your brain telling you something is not normal (and possibly dangerous) based on sensory feedback. It is interesting to note that it also seems the more acutely aware you are of the pain signal, the stronger that signal becomes (I.E. whether that increased focus is because of a specific previous instance like the snake bite in the story, or because of something a bit more akin to navel-gazing, which I’ll just call “hyper-self-awareness”). I.E. it hurts more, the more you react to it, and the reaction to future instances of a “pain-causing stimulus” is more immediate and severe the more you focus on it.
Conversely, it also seems that if you accustom your brain to a certain level of input (E.G. the degree of a stretch, or the effort of a heavy lift or hard workout), it will have a new “normal” to reference against, and the “pain” signals will diminish. With regards to stretching, there is a name for this theory – the Sensory Theory of Flexibility, as examined in the study referenced here. With regards to exercise/sports-related pain, you might call this a logical reason for “walking it off” – thanks, Nick Tumminello, for putting that terminology back in my head – HAHAHA! It may also be another explanation for why lower-intensity activity can help recovery from workouts (along with the obvious benefits of increased circulation, etc.).
So the next time you experience pain, stop and think about the logic behind the degree of your response – consider the cause, and think: is this response reasonable, or is my brain blowing this out of proportion? Do I still have full/adequate functionality/ROM? It might be worth “walking it off” and seeing what happens. (Of course with the disclaimer that you do this of your own informed volition – if you think you really shouldn’t do something, don’t! If you think you have a legitimate injury, seek medical attention.)