Chinshin, which can be translated to dropping body, consists of these two Kanji: 沈身. In English we use the term Body dropping, which is quite visible is most cases but invisible in other cases. If you speak of Chinshin there are basically two kinds to distinguish, of which the first is a visible big movement (from hereon called "Body dropping) and the second is an -almost- invisible small movement (from heron called Internal body dropping).
In this blog I would like to zoom in on Body dropping. Body dropping is the first to learn before you can proceed to Internal body dropping. As Sakagami sensei told me several times: "The big includes the small, but the small does not include the big".
Another term that is used is Vertical dropping, which emphasises the direction of the dropping movement. Imagine standing up straight and leaning to a random direction. Your body will fall and eventually diagonally downward. This is a bigger distance than straight down and it is also slower.
Within Karate, 沈身 therefore has the meaning of explosive and immediate dropping of body weight.
The term vertical dropping refers to the perpendicular dropping of the body or actually the body weight. The function of this technical ability is to increase impact and it is also a helping aid to maintain kinto. Chinshin can be used to:
Note that you do not always have to drop deeply, say from Shizentai into Shiko dachi. Although that is a good way to use it and easier to learn, eventually you need to be able to drop with a smaller movement. For example, even Sonobazuki contains dropping movement. Hence, once you advance you need both the skill of dropping deeply and dropping in a small movement, so that you have a choice which one to use to suit circumstance.
To apply Chinshin in Sonobazuki, you can use the following method, which I learned from Nukina sensei.
The demonstrated trainingmethod on this page is also demonstrated in this video. In the video, I also share a variation that allows you to drop more deeply and is easier to learn. Furthermore, -apart from explaining Chinshin from a different angle- I share a nice little fact of Ishikawa sensei's experience with Ohtsuka sensei.
To conclude, I would like to share the following variation on Sanbon kumite Jodan uke 1. Instead of using three steps, we will demonstrate this version as an Ippon kumite, executed from Hidari hanmi ai gamae.
This Ippon kumite is based on Ishikawa sensei's way and is absolutely different than Suzuki sensei's way. Although the handmovements are identical (of the Sanbon version), the body movement of the 'first' movement is fairly different. Suzuku sensei used to use Shizentai and leaned back while executing Nagashi uke and Urazuki, while Ishikawa sensei used Shiko dachi. It is not the stance that matters though. What matters is the body movement that causes this stance.
Ishikawa sensei used a Leg switch using Chinshin visibly to control Maai and stopping the backward movement. If you use this way, it is easier to adjust to the movement of your opponent (who might enter deeply or fall short).