Sitting

Sitting is a rest posture supported by the buttocks or thighs where the torso is more or less upright.

Sitting on the floor
The most common way of sitting on the floor involves bending the knees. One can also sit with the legs unbent, using something solid as support for the back or leaning on one's arms.

Sitting with bent legs can be done along two major lines; one with the legs mostly parallel and one where they cross each other. The parallel position is reminiscent of, and is sometimes used for, kneeling. The latter is a common pose for meditating.

Parallel legs

 * Seiza (正座) is a Japanese word which describes the traditional formal way of sitting in Japan. Sitting in seiza is kneeling on one's own lower legs, with the feet under the buttocks, toes pointed backwards.  To sit in seiza for any length of time requires careful positioning of the heels under the sit bones of the hip, to minimize circulation loss. A related position is kiza (跪座), which differs in the tops of the feet being raised off the ground.
 * Vajrasana (Diamond Pose) is a yoga posture (asana) similar to seiza.

Cross-legged

 * A common cross-legged position is with the lower legs folded towards the body, crossing each other at the ankle or calf, with both ankles on the floor, sometimes with the feet tucked under the knees or thighs. The position is known in several European languages as tailor style, from the traditional working posture of tailors; compare tailor's bunion. It is also named after various plains-dwelling nomads: in English Indian style, in many European languages "Turkish style", and in Japanese agura (胡座). In yoga it is known as sukhasana.
 * The lotus position involves resting each foot on the opposite thigh so that the soles face upwards. If only one foot is brought into this position, it is called a half-lotus position. This position is common in yoga and meditation.
 * The Burmese position, named so because of its use in Buddhist sculptures in Burma, places both feet in front of the pelvis with knees bent and touching the floor to the sides. The heels are pointing toward pelvis or upward, and toes are pointed so that the tops of the feet lie on the ground.  This looks similar to the cross legged position, but the feet are not placed underneath the thigh of the next leg, therefore the legs do not cross.  Instead, one foot is placed in front of the other. This  is a popular sitting alternative for those less comfortable with the use of the Lotus or half Lotus positions in meditation and yoga.
 * Zazen, the Japanese word for "sitting meditation", is a form of meditation rather than a particular posture. During zazen, practitioners may assume a lotus, half-lotus, Burmese, or seiza position.

Sitting on a raised seat
Most raised surfaces at the appropriate height can be used as seats for humans, whether they are made for the purpose, such as chairs, stools and benches, or not. While the buttocks are nearly always rested on the raised surface, there are many differences in how one can hold one's legs and back.

There are two major styles of sitting on a raised surface. The first has one or two of the legs in front of the sitting person; in the second, sitting astride something, the legs incline outwards on either side of the body.

The feet can rest on the floor, or on a footrest, which can keep them vertical, horizontal, or at an angle in between. They can also dangle if the seat is sufficiently high. Legs can be kept right to the front of the body, spread apart, or one crossed over the other.

The upper body can be held upright, recline to either side or backwards, or one can lean forward.

Posture


Alice, the protagonist of Alice's Adventures in Wonderland, is representative of children who were once admonished to "sit up straight."

Recent studies indicate, however, that sitting upright for hours causes increased stress on the back, and may be a cause of chronic back pain. Researchers have found that a "135-degree back-thigh sitting posture" was the best posture to avoid back problems&mdash;that is, leaning back in the chair 45 degrees. Researchers found that the 90-degree position contributed most to strain on the spine, neck included, while the 135-degree position was the most relaxed.

Optimal posture while sitting is now referred to as neutral spine.

Variations
Variations of the above include an aside variant with the legs resting above and beside the armrests, or the anti-authoritarian posture of reversing the chair and one's legs in front of the back of the chair.

In mythology
In various mythologies and folk magic, sitting is a magical act that connects the person who sits, with other persons, states or places where he/she sat.

Sitting defecation posture
The sitting defecation posture involves sitting with hips and knees at approximately right angles, as on a chair. Most Western-style flush toilets are designed to be used with a sitting posture. The sitting posture is more widespread in the Western world, and less common in the developing world. Toilet seats are a recent development, only coming into widespread use in the nineteenth century.

Health effects of sitting
Recreational sitting, as reflected by television/screen viewing time, is related to raised mortality and CVD risk regardless of physical activity participation. Inflammatory and metabolic risk factors partly explain this relationship.