Just like me, Moshe Feldenkrais was both a therapist and a Judo black belt. Unlike me, Feldenkrais was a genius. Everything that I have ever read by or about Feldenkrais has been mind-blowingly thought provoking, including his book, Awareness Through Movement, and his Judo Groundwork book which is interpreted in this essay at Judoinfo (this is cool too). Any of Feldenkrais' stuff that I read once I have to read over and over.
In Awareness Through Movement, several chapters are dedicated to the questions, "What is good posture?" and "What is good motion?" The following are some of the most interesting points (to me) from those chapters. These seem to be applicable to both Judo and Aikido and speak particularly well about aikido.
- Effective action improves the ability of the body to act.
- Reversibility is the mark of [good] movement.
- Light and easy movements are good.
- There is no limit to improvement.
- Use large muscles for heavy work.
- Forces acting at an angle to the main path cause damage.
- Superfluous efforts shorten the body.
- Concentration on the aim may cause excessive tension.
- Performance is improved by the separation of the aim from the means.
- Lack of choice makes strain habitual.
Whenever you think that you have mastered something in aikido, I recommend you choose any one of these ideas and consider it carefully in the context of the motions in your technique. See doesn't the whole technique fall apart for you. See isn't your aikido better when you finally get it reassembled in accord with Feldenkrais' ideas.