First, take a look at what muscle groups were monitored. Trapezius (green); latissimus (blue); biceps (grey); triceps (red). Note: I think this was poorly done. No part of the deltoid is monitored. And only the right side of the body was monitored. Both of these were big flaws in my opinion.
Kuroda Tetsuzan is amazing. He far out classes me. But if you tested me, I am very confident that the muscle usage would be closer to Kuroda's than to the "amateur's."
Notice that the "total movement" is the raise and cut. The first half of the graph is the raise, the middle is the cut.
The amateur has unnecessary activity in his body, i.e. tension.
Kuroda's trapezius does activate on the raise. I would also like to point out that it is easy to see that Kurodo is contracting his deltoid (I would say a rather hard contraction) in the picture of Kuroda raising the sword.
What really is so remarkable about the results of this "study"?
Where do we see the "IP/IT/IS" tells? Do we?
being meaning to respond to this, but was tied up and no, nobody practiced hojojutsu on me. it would only encourage me to be bad.
the significant of the study for me, besides the inefficiency of the amateur muscle usage, was that Kuroda sensei using a slight different set of muscle to do certain thing. sure, some are overlap, but not all. in the previous thread which this thread spawned from, where i gave example of picking up the spoon. before i mentioned it, did you thought of getting underneath the spoon and push it up? as mentioned many times before, that IP/IS involved lots mental aspect because it follows this principle "desire leads mind. mind lead chi/ki. chi/ki leads motions" notice the mind part. if your mind form an imagery to make your body to activate various muscle groups, it depends on the imagery, your body activates different muscle groups, wouldn't you agree? for me, when i pick up the spoon, i activate the same group of muscle as i would picking up a large sack of potato on the floor. and yes, we already talked about efficiency and my answer was referencing the thread where Vlad mentioned about different set of responds. this is really about the "do", i.e. being versus doing. as an experiment, you can ask friends and neighbors and any athletic, including olympic class, to pickup the spoon. then ask them afterward, did they thought of getting underneath and push it up?
you would think, what different would that make? it makes the whole world of different. it's how IP/IS folks use their mind to direct their body to perform a function.
the other example i mentioned was about punch in the stomach. does trained folks crunch their stomach muscles or "inflate" them? i mentioned that i used to crunch, but now inflate, i.e. the balloon man model. ask boxers if they crunch or inflate?
here is another thought to mull over. a push is a pull in the other direction, i.e. a push in the front = full from the back. and experiment to try, when someone pushes you from the front, try focusing on resisting a same pull from the back and ignore the push. ask a linebacker if he/she/it focus on the push in front or the pull from the back? and yes, they do train to pull heavy things, but did they do it when there is a push from the front?