Do you know what fascia is? If you do you are in the minority. Yes ago I had a plastic surgeon as a client debate with me the ability of this tissue to change. His medical training told him one thing, the disappearance of his chronic back pain from his Rolfing sessions told him another thing.
Fascia is the connective tissue that holds everything together. It becomes scar tissue when there is an injury or repeated stress. Here is an excellent article in Running Times explaining why it is important to runners.