Gyakuzuki is the practice of how to deliver your maximum energy potential with rotation. In gyakuzuki, you have to rotate more than in junzuki, so your stance has to be a little shorter and a little wider then junzuki dachi. We simply refer to gyakuzuki dachi. This is the physical facility for rotational movement. There are at least 4 reasons why to use gyakuzuki dachi instead of junzuki dachi. The most obvious and the one that should be always mentioned to beginners is to create space for koshi to make proper movement. The second reason is that when ‘closing’ the body (moving koshi in direction of the front leg), junzuki dachi will cause too much strain on the front leg muscles. The third reason is that gyakuzuki dachi provides better stability when closing the body. The fourth reason has to do with the development of your internal muscle, which is inevitably connected to the position of your front foot and knee. Ultimately you have to generate your momentum in a smaller movement.