Recently I was reading some interesting Karate articles and came across the term 'chinkushi'. On reading the article I discovered that the word describes what I have been teaching for years without knowing that it had a name. Further even than that, I was shown the technique by a practitioner of Shotokan and have not seen many any others teaching it. The closest I have seen is Erle Montaigue demonstrating fajing. It is similar to the relaxed striking in Systema and I have no doubt it is taught in the internal Chinese martial systems, especially by practitioners of the one inch punch.
The word chinkushi is Okinawan and part of the old Okinawan language.
So, what is chinkuchi?
The article I was reading went on to quote several well known martial artists.
Higaonna Morio, 10th dan Goju-ryu:
“This expression [chinkuchi] is used to describe the tension or stability of the joints in the body for a firm stance, a powerful punch, or a strong block. For example, when punching or blocking, the joints of the body are momentarily locked for an instant and concentration is focused on the point of contact; the stance is made firm by locking the joints of the lower body – the ankles, the knees and the hips – and by gripping the floor with the feet.
Thus a rapid free-flowing movement is suddenly checked for an instant, on striking or blocking, as power is transferred or absorbed. Then the tension is released immediately in order to prepare for the next movement.”
It is hardly surprising that this is exactly what Masaji Taira Sensai taught us when we trained at the Jundokan, Higaonna's original stamping ground.
Another description from Arakaki Kiyoshi, Karate writer:
“A simple explanation is, when punching for instance, to contract the muscles used when punching (especially the triceps and the trapezius), increasing the speed of the punch or block from within your own body."
And from Tokashiki Iken, Karate historian:
“When punching, the most important thing is that the “koshi” [hips] are in it, and that chinkuchi is being utilized. Chinkuchi, in a word, means to contract the trapezius, the triceps, the pectoralis major, etc. when thrusting the fist out. At that time, the armpit must also be closed when punching or blocking.
This means that a punch with chinkuchi has an instantaneous increase in power. This is called “one cun power” [one inch punch] and causes a great destructive power upon the opponent’s body.”
The author of the article summed it up as thus:
"Chinkuchi is about knowing when to relax… and when to tense.
The skill of switching between these two, by using the whole body, is called chinkuchi."
So how does all this translate into training? Well, we train to develop an explosive twisting movement of the hips. This requires the body to be relaxed. (If not, the turn of the hips will turn the entire body and naturally this is a much slower movement.) the turn of the hips generates torsion in the spine that in turn starts to rotate the shoulder girdle. Now the arm starts to move and, because it is relaxed, accelerates towards the target. A fraction of a second before the moment of impact the fist is clenched and the full power of the strike is transferred to the target. Immediately the body returns to its relaxed state.
Additional force is applied by the slight movement of the body toward the target.
The original article can be found here