Nick Simpson wrote:
everything I have read/seen/been taught about cutting with a sword states that the wrists cut, not the arms or shoulders as that encourages strength rather than technique. I use a shinken this way and it works fine, very quick and accurate cuts.
Using wrist movements to cut with a shinken or iaito is unorthodox, I would say. Traditionally, the cutting with the sword should be done with wrists fixed and a big arm movement (well, the center working, and the shoulders relaxed, of course). That is to be able to cut through, among other things.
In my experience the shinken/iaito cut is not significantly slower than the shinai strike (from a jodan kamae position) - but the shinai is faster when doing multiple strikes. There are ways around that, when using the shinken/iaito, but that would be deviating too much from this thread.