We did some coaching rotation so I got to do a bit of training on my achilles heel - Toranoissoku. I am gradually getting used to the action of the sword but being quite tall (and too heavy for my skinny little legs) I often lose balance stepping back. I worked at ensuring my foot went straight back on Wednesday by trying to feel my foot pushing out. Inevitably it is the angle of the hips which has so much effect. I'll explain more.
While this form seems to rely on a strong sweeping action of the sword, if the left hand and side of the body isn't used adequately then the sweep loses kime and tends to swing. I have been shown how using strong sayabiki, the sword itself gains stability and focus. However, overturning and thereby rotating the hips has the tendency to point the rear foot back towards the centreline of the body thus creating a narrow and unstable posture. See below.
However, if sayabiki is inadequate then the whole sweeping action loses it. A simple concept is to keep the hips square while turning the shoulders. This seemed to do the trick. In fact relative to the hips, this created an even stronger sayabiki than turning the hips (of course).When I had done this bit a few times and got the feet and hip position right, it showed obvious improvement in the sword control.
The next bit also causes problems. While I believe that a quiet return leading to a devastating cut concludes Inazuma quite appropriately, Toranoissoku requires a rapid return and cut. The opponent hasn't been cut themselves at this point, only their sword has been balked and a quick counterstrike is necessary.
I refer readers to Richard Stonell's brilliant article on Eishin Ryu at this point. Well worth a read through and a study to get the right taste to these forms...
http://kenshi247.net/tag/eishin-ryu/
My teacher tried to get me to do this, fast and light, using the downward action of the body to augment the upward lift of the sword. That also sounds easier than it is as often the sword will get into place first and park itself while the body gets seated. I managed to get it right a couple of times and I could feel when it was working and when it wasn't (with a typical ratio of 1:100). I fully believe that the overall success of this form relies on having strong legs and hips and so it is certainly work in progress.