Shizen-hontai (自然本体) is the basic natural posture and is the essence of the shizentai-no-ri, the first of the basic principles. Feet are about shoulder width apart and the arms hangs relaxed at the sides. It is important to maintain the feet pointing outwards at about 45° so that the weight will naturally project over the big toes. Under no circumstances should the outer edge of the foot be use to support the wheight. This happens if the feet are pointed directly to the front. The knees and hips should be relaxed and slightly bent to facilitate maximum mobility.
Maintaining a natural posture while fighting is not something special to judo or even new. It has been considered to be of major importance to the disciplines of combat by many for a long time. In his Go rin no sho or Book of five rings from 1645 in translation by Victor Harris, Miyamoto Musashi (1584-1645) famously wrote:
- "In all forms of strategy, it is necessary to maintain the combat stance in everyday life and to make your everyday stance your combat stance. You must research this well."
"Jigoro Kano, the inventor of Judo, regarded correct stance as so important that he made it one of his three central principles of Judo." This is quoted from Syd Hoare's Judo: teach yourself. Posture in general and Shizen hontai in particular is described early and given some emphasis in most judo books.
- In Judo: Japanese Physical Culture by Sumitomo Arima from 1904 as it is reproduced in A complete guide to judo by Robert W. Smith published in 1958; "Posture and the state of mind" is the first of the important principles and described as follows:
"One must keep one's posture absolutely free and unrestrained. In other words, the body ought not to be held stiff or inclined but should be capable of standing long strain..."
"As this posture is the most endurable of all the postures and capable, whenever necessary, of answering various changes in bodily movements, it is imperative for one to be mindful of returning to it in order to make fresh operations, offensive and defensive."
- Gunji Koizumi discuss the basic natural posture under the heading of balance in his Twelve judo throws and tsukuri from 1948 as reproduced in the Journal of Combative sport, march 2002:
"It may be said that a human body, in its upright position, is in a balanced state when the trunk of the body, in the upright posture, is held directly above the feet. However, the nature of the human body is such that, if pulled or pushed, especially the upper part, it is not an easy matter to retain the state of balance without moving the feet. For this reason, in judo the feet are kept about 18 in. apart, so that, while they form a suitable basis for the body, they can be moved easily and swiftly, and the wheight of the body can be transferred from one to the other as circumstances demand."
- "Correct you posture" is the third of Kyuzo Mifunes "Seven disciplines" in The Canon of Judo, 1958, english edition from 2004:
"The correct posture in judo is natural and flexible, and all pretensions must be avoided."
In the section "Postures" Mifune 10th dan continues:
"This is the most important posture, and foundation of judo training. It is a comfortable and natural posture, expressing the natural form of the human body[picture reference deleted]. Point your toes slightly outwards, relax the shoulders and do not tense the joints of the knees or hips." Where after he goes on at some length about the details of shizen hontai and shizentai".
- In Judo in Action by Kazuzo Kudo 9th dan, 1967 the importance of the basic natural posture is discussed under "Body movements":
"In judo walking methods, on the other hand, we move our legs, hips and bodies forward or backward all at the same time... The first thing to remember is to maintain the natural body position. Earlier we explained the natural position we said that you should not let your weight fall on only one or the other of your feet. This applies not only to standing perfectly still but to walking as well.
- Best judo is a book many use as their basis for competitive technique. Written by Isao Inokuma and Nobuyuki Sato in 1979 it has a section on posture:
"Shizen Hontai: Spread both heels about 30 centimeters (1 ft.) apart. Point the toes of your feet naturally outward and place teh wheight of your body equally on both feet. Your knees and hips should be relaxed so that you can, at any time, step freely forward or backward. This is the fundamental posture of judo."
- Syd Hoare spends a page of his Judo: teach yourself from 1980 on "How to move around the mat" which handles shizentai:
"...this stance should be maintained as much as possible. To a beginner this rule may not seem very important, but if time is taken out to pbserve inexperienced people in Randori, you will see that the natural tendency when fighting is to crouch and spread the legs. The crouching defensive stance, known as Jigotai in Japanese, suffers from two main defects. First, mobility is reduced, which means it is not a good position to attack from, and secondly, it is not such a good defensive position as it seems. It is better so stay upright and move out of the way of attacks than to sink into this sitting-duck position."
"This means 'posture' or 'stance'. In judo the best fighting stance is the natural stance or 'shizentai'. This has been equated to the Mu no Kamae of Kendo (Japanese sword fighting), and means the Posture of Nothingness. It is the posture that shows nothing to the opponent, giving no intentions away." He goes on to discuss the strategic implications of assuming a specific guard and thus alerting the opponent to how you may attack.
- In Kodokan Judo from 1986 it is described briefly:
"The basic judo posture is taken by standing naturally, heels about 30 centimeters apart, arms in a relaxed position at the sides."