The Jan de Jong Martial Arts Fitness (an offshoot of the Jan de Jong Self Defence School) website explains: 'There is a direct relationship between the armed and the unarmed self-defence arts and these unique techniques will be explained and demonstrated during the course of the classes.'
not alone in suggesting there is a direct relationship between armed and
unarmed self-defence arts. Aikido is an obvious example where some
practitioners focus on the supposed direct relationship between armed and
unarmed self-defence arts.
I'll refer to Shihan Jan de Jong OAM 9th Dan (posthumously 10th Dan) who used to criticise those martial arts that suggested their tactics and techniques were based on the fighting tactics and techniques of animals. As he would say, we are not animals. We are not tigers, eagles, preying mantis , or any other animal. Even though we are related to monkeys, we are not monkeys. Monkeys cannot form a fist, we can, and studies have shown that the ability to form a fist is a distinct survival advantage over monkeys and apes. Why give away that survival advantage for a principal?
In like manner, our limbs are not weapons made of steel. They do not have the ability to cut, slice, or stab. Juxtaposed to that is that the sword does not have the ability to unbalance an opponent other than to directly oppose their force. Why would you base your self-defence tactics on techniques on a method that is clearly not representative of your resources?
The Jan de Jong Jujutsu grading system included a grading, Ken Tai Ichi no Kata. The kata of sword and body. It's supposed to demonstrate the similarities between sword techniques and unarmed techniques.
The explanation of the purpose of the kata is flawed.
The core of all learning is the identification of similarities and differences. The kata should be demonstrating the similarities AND THE DIFFERENCES between armed and unarmed defences.
There are similarities between certain tactics and techniques but there are also differences, BECAUSE OUR UPPER LIMBS ARE NOT SWORDS.
A classic case in point is that it is very difficult to unbalance an opponent with a sword other than to directly oppose them. This resulted in some 'shoe-horning' by the instructors at the JDJSDS when they attempted to reconcile the physical unbalancing methods in the unarmed defences with those of the armed defences.
Only in the martial arts would this discussion ever arise.