Seiza (literally “proper sitting”) is the Japanese term for one of the traditional formal ways of sitting in Japan. To sit seiza-style, one must first be kneeling on the floor, folding their legs underneath their thighs, while resting the buttocks on the heels. The ankles are turned outward as the tops of the feet are lowered so that, in a slight “V” shape, the tops of the feet are flat on the floor and big toes sometimes are overlapped, and the buttocks are finally lowered all the way down. Depending on the circumstances, the hands are folded modestly in the lap, or are placed palm down on the upper thighs with the fingers close together, or are placed on the floor next to the hips, with the knuckles rounded and touching the floor. The back is kept straight, though not unnaturally stiff. Traditionally, women sit with the knees together while men separate them slightly (Wikipedia).
http://seesaawiki.jp/onnanawa