Disclaimer: Lots of ki crap to follow. If you feel the need, you may avert your eyes now. Consider yourself warned.
Ah, a subject dear to my heart...
I just got back on the mat a month ago, after breaking my clavicle in a bad roll at the end of July, then rebreaking it a month after stepping back on the mat in October (I came back a bit too soon, and my clavicle didn't like that
For all of this time (in total, a period of six months off the mat) I came to nearly every class (2 hours, three nights a week) and watched, which kept everything fresh in my mind. For the two-month period after the first break, I could think of nothing but getting back on the mat, and didn't do much in the way of finding things to work on off the mat. After the second break, however, my sensei leant me a book on ki training (A Road that Anyone Can Walk: Ki
) that had excellent descriptions of breathing and meditation exercises, and just some great concepts to think about (at least in the first half. At one point it gets a little high-and-mighty and preachy *shrug*). I worked on posture, breathing, relaxation, ki extension in normal activities (eg walking down the street and connecting with the people walking around me), keeping weight low, and a host of other things, just taking a moment to pay attention to them once in a while. I also started running through jiyu waza in my head ("All right, so from this attack, if I enter inside deep, I can do this and this and this..."), doing something like the visualization training that some athletes do. And when I got back on the mat, not only was I hardly rusty at all (just a little atrophied), I was actually better
in technique than I had been before (less muscle, more flow, better timing). I didn't do so much as a single ki exercise or tai sabaki while off the mat--no physical practice at all--and still I had improved through all the other things I was doing.
Technique isn't the only way to practice Aikido... but I'm sure you already knew that.
Good luck, and feel better!