In the East, a traditional way of washing clothes was to soak them in soapy water, jerk the dirt out of them, rinse and then dry them in the sun. In India the jerk was given by whirling the wet cloth in the air and slapping it down on to a clean flat stone. This does get the dirt out, but does not improve the life of the cloth. In Japan in the last century, they used to pummel the clothes with the fists to do the same thing.
I heard Dr. Kano tell how he had observed the maids in his house doing this. He stopped them, and showed them how to hit the clothes with the edge of the straight hand, the thumb turned in. After a few weeks he gave some more instruction, on how to use the whole body in the blow. He checked their progress from time to time, and some became quite expert at the movement. We should note that he said they were practising the action with attention, not just repeating it mechanically.
He further related how one evening one of them visited a sick parent, and had to return through the Tokyo streets at night. She took a short-cut through a dimly lit street. A young tough jumped out from the shadows, and caught her long sleeve. Without thinking, she found her body instantly turning towards him, and her right arm delivering the same blow it had so often given to the laundry. But this time it was on his outstretched arm. The arm was broken. This was confirmed next day by asking the local bone-setter: ‘an unusual injury,’ he said.
I heard Dr. Kano give this as an example of what he called in English ‘automatic secondary application’; in other words, a movement practised on judo principles which was useful in quite a new situation, and which went into effect simply by the need of the moment, without a conscious decision.