Re: Training when you can't train (injured newbie)?
I have become very intimate lately with Injuries. I train fairly rigourously in MMA, BJJ, and Judo and quite honestly, turning 44 next week, in the best martial shape of my life, and I am also having to slow down if I expect to be able to train for the next 20 or 30 years.
Starting out in any martial adventure like aikido is using parts of your body and core that for most folks they have never actually developed or used. It simply takes time to develop these things.
"Being in Shape" is more than about being in good cardio shape, or strength shape. There is a linkage between these things, plus you are leaning new pattern of movement, your brain is having to learn stuff and your muscles, fascia and structure all have lots to learn and develop.
It sounds like to me that you have the right ideas and attitude towards all this, just keep at it, do what you can do, and things will develop and you will find a year from now, five years from now, that you are doing things you thought were hard.
On top of that, I think stability balls are really good things for developing coordination, kinestic awareness, and the physciality you need to move in martial endeavors. Low impact, you are supported, and you can adjust your training easily for your skill level.