Saturday I fell down a flight of stairs. And landed, mostly safely, on my ass. Well, I suppose on my coccyx, really. Boom. And, well, running isn't so easy right now. Walking isn't either.
The question is, though, how do you deal with this kind of thing? It's been rough for me, since I do a lot of thought clearing when I'm running. In many ways running is meditation for me--ideas pass through my head, usually without judgment, just as ideas. By the time I'm done running, I've usually gotten through some of the things that were clogging up my thoughts. And this is good, because it lets me get on to things that are more interesting and more useful and more enjoyable.
When that forced meditation is taken away, I have a lot more time to worry about things. The key to responding to this is to try to fill that time usefully otherwise. The difficulty lies in the loss of energy due to the healing process.
Writing, I find, is a useful way of dealing with similar thought clearing processes. It's not meditative in the sense that there is a strong analytical/judgmental aspect to the process of putting my ideas on paper, but in ideal circumstances, I am able to keep the judgmental aspects on the page and am free from judging the writing itself, and in this sense it allows the ideas to express themselves without judgment.
Thinking about Murakami's book, I don't recall that he really talks about injury and being unable to exercise. He talks about some injuries, but it doesn't seem in the sense that any of them really stopped him from running. He talks about worrying that an injury might keep him from running a race, but not about just the gap in a regular schedule when a common practice is dropped out. I wish I could keep up running when injured, but some injuries are not well served by use. I wonder how differently he feels when laid up.