This is an English translation of Part 2 of a seven-part article by Nakamura Sensei, 7th Dan. The link to the original article in Japanese is: http://www.geocities.jp/gazo_asidachi/kumagro_niki/iyashino_kendo/iyashi_01.htm. Posted with permission and translated by KendoNotes.
First, on kamae.
In the standing position with your left foot and right foot, please place your weight, with a ratio of 7 to 3, on the left (back foot) vs. the right. As if the right foot could be moved at any time. Please remember this since the right foot will play an important role henceforth when attacking (seme) and responding (ouji). In the upper body and, in particular, in the shoulders and arms, please release any tension there completely. Note that when in kamae, if the wrists (and hands) are squeezed too tightly, tension will surely return (to the upper body). I think that (sufficient power) to the point of holding the shinai in kamae is good. If tension creeps in, one cannot act with instant movements. Furthermore, one’s movements can be discerned by the opponent. Please adopt a natural kamae like the willow tree that does not oppose the external power of the wind. Even if one’s shinai is flicked away, the attitude to have here is an one of naturally returning to the original position without opposing that force. When this happens, the opponent thinks “this dude is good.”
In your standing position, please make sure not to lean forward. Typically, we are told to extend (straighten) the back of the left knee (popliteal fossa). However, since over-extending it causes the movements to be awkward, please hold the knee flexibly with a light amount of extension.
Please place the left fist, as much as possible, in the area below the belly button. I think it is good to have the ken-saki (shinai tip) at the usual height.
The point is to remove any tension in the upper half of the body. This is quite difficult. The left heel should feel as if it is floating lightly. Please be careful because if the heel is raised too high, the body weight shifts to the front foot.