To gain a little more understanding of the mechanisms at play here, check out this video where leading pain scientist Lorimer Moseley begins to explain our current understand of pain which is revolutionising treatment.
Separating fact from fiction with Proffessor Peter O'Sullivan
This is one video in a fantastic series by Professor Howard Schubiner which can all be found on Youtube.
A very clear explanation of brain plasticity with Dr. Norman Doidge.