上段の構

Jodan-no-kamae may be either right or left handed. With the left hand or hidari-jodan the sword is raised above the head and the left foot advanced. With right handed or migi jodan the right foot is advanced. Both positions are taken with a feeling of looking down on the opponent with a spirit resembling a raging fire. It is used to suppress the opponent with the threat of striking his sho-men. It is essential to suppress the opponents will and action with ones own and to give away not even the slightest opportunity to attack.

中段の構

Chudan-no-kamae, a threat is projected at the opponent’s throat by way of the point of ones sword. The left fist is placed at about a fists distance from the naval and a little below. The feet are positioned with half a steps distance between them, the right foot to the front. The position should be taken as if one had come to a natural halt while walking.

下段の構

Gedan-no-kamae, the tip of the sword is aimed at a point a few inches below the knees of the opponent, and its use is similar to that of chudan-no-kamae. Rather than being a position from which to launch an attack it is more suitable for defense and allows a free reply to an opponents moves.

This covers the explanation of the three kamae otherwise known as 天の構 ten no kamae (heaven), 地の構 chi-no-kamae, (Earth) and 人の構 jin-no-kamae, (Man).

陰の構 （八祖の構）

One of the In-no-kamae is Hasso-no-kamae which is similar to Hidari jodan with the right fist lowered to about level with the right shoulder and the left hand held in front of the pit of the stomach. From this position the opponent is observed and countered.

陽の構 （脇の構）

One of the Yo-no-kamae is Waki-no-kamae, in which the sword is held to the right of the body with the tip aimed down to the lower rear.  The right foot is retreated to leave the left foot forward.  Among the traditional styles and disciplines of swordsmanship there are many variations of kamae but those mentioned are above are the 5 main or root positions. (Noma Higashi, The Kendo Reader)

Noma Hisashi mentions that the first three kamae are know as the ten-no-kamae, chi-no-kamae, and jin-no-kamae.  This is do to the locations that the blade is held, chudan-no-kamae being the kamae in the middle of heaven and earth.  Later Noma Hisashi mentions the In-no-kamae and yo-no-kamae, in and yo better know as yin and yang.  The point of the kamae are for attack and defense and should be used with the spirit and the purpose of cutting the opponent down.

There is deeper significance to these kamae, but I rather not attempt to offer any more than this superficial explanation at this point. 

You can find a free copy of Noma Hisashi’s The Kendo Reader by clicking on the link.  There are various copies floating around in print, but they are sometimes difficult to find.