Diagonal tension in Uki-waza

Mae-otoshi – Sumi-otoshi – Hiki-otoshi

The integration of our bodywork into Uki-waza will generate extra power into the waza. This power is derived from “tenshikei” or the power generated through internal body turning, stretching and releasing. This internal turning follows a diagonal spiral line  or in other words : diagonal tension.

Diagonal tension is one of primary factors for the skill of cutting with a sword. It is Monjuro Morita, a famous kendoka who wrote a book on kendo covering diagonal tension.

 

Monjuro Morita (1889-1978)

Adapted from Kenji Tokitsu book : Miyamoto Mushashi, Myth & Reality

Morita Monjuro and his attempt to understand Musashi’s Single-Cadence Strike. Monjuro believes that Musashi had perfect handling of the body because he knew how to use the diagonal tensions of the abdomen/thorax.

The tanden and the koshi, located on either side of the body, form one set in practice. Each muscle use of koshi is transmitted to the tanden by stimulating pressure, which activates positively different parts of nervous systems.

Tanden and the musculature of the koshi form a unity, but their roles are not the same. The tanden controls the koshi. The training of koshi is synonymous with the training of the tanden, center of the body, and thus it becomes a training of body and mind … We can say the training of each technique strengthen the muscles of the koshi and the tanden. Which has almost the same effect as to strengthen the tanden practicing zazen. If the practice of Budo remains at a mere technical manipulation, the effect can not be the same. By producing the art of the koshi and tanden, we can strengthen our mind and body.

To hit properly from the tanden and koshi, we must use a perfect structured body and a perfect handling of the sword. This is a gesture that is produced in accordance with the two forces that go diagonally right leg left arm, left leg and right arm.

The perfect handling of the sword is produced by the integration of three elements: the rotation of koshi, diagonal tension produced by this rotation and displacement of the body.

The perfect handling is achieved by integrating the tensions of the body diagonals that cross the legs to the arms. Applying this principle, I discovered that the force spontaneously filled the tanden, and my kendo has been completely transformed.

The Key to Power: Spiral Movement and diagonal tension

Spiral movement is defined as a three-dimensional curve in space around a central axis. A spiral elongates as it turns so it has a built-in expansive quality to it. Spiral movement is a type of movement we naturally and frequently perform throughout the day.

When we turn our body to shake another’s hand, you should feel the spiral not only in your upper body but all the way down to your feet. 
While the entire body should spiral, the upper body (i.e., from the waist up) will turn more than the lower body. This creates a dynamic stretch of the muscles. It is like stretching a rubber band with all the resulting stored potential energy. The separation of the upper and lower body is a major factor in generating power from spiral movements. But keep in mind, the body is functioning as a whole unit.

The separation skill is possible when we can control the lower part of the body. The control can be explained as stretching and releasing the muscles of koshi and tanden.

Contracting muscles can not spiral.

Contracted muscles can only rotate and twist. In contrast, lengthening (particularly lengthening of the whole spine) is what allows the spiral to occur and give the possibility to generate power. “A spiral elongates as it turns so it has a built-in expansive quality to it.”

Maybe you understand now why we have to keep the body in an upright posture. By taking up a curved posture, the tendency is to contract muscle of the torso and no power can be generated from spiral movement and diagonal tension. By adopting an upright posture we can generate power from spiral movements and diagonal tension.

How to apply spiral movement and diagonal tension in Uki-waza

Stretching and releasing following a diagonal pathway is the key to powerful “otoshi” techniques. Remember not to use muscle contraction during the throw. It is about releasing the stored power in the lengthened muscles.
The power in the throw can be compared with the power of a waterfall.

 

Mae otoshi

The setup for mae otoshi is creating diagonal tension. By stepping forward the tension can be released and becomes kinetic power.

Sumi otoshi

Sumi otoshi is an almost exaggerated example of “tenshikei”.

Hiki otoshi

Remark the footwork to improve the diagonal tension. When releasing the tension and stepping back, tenshikei becomes kinetic power.