I am glad that someone posted this video of Miyoko Shida.
As you can see the title on the page itself labelled it as a feat of concentration. However, I would say its a feat of sensitive feeling. Why?
Its because if you can concentrate but you can’t feel then I doubt that this feat can be performed. In fact, if anything I would say that this is not so much a case of single minded concentration but diffused non-concentration i.e. your mind must be able to focus on many things at the same thing. This is something that Takuan wrote about in relation to the thousand hand Buddha.
In many ways this is similar to the practice of Taijiquan. For example many have heard of threading the 9 pearls but if you ask them what it means especially in practice you will find many explanations many of which treat it as an externalized exercise.
It is not uncommon that many think of threading the 9 pearls as a process i.e. you thread one pearl at a time. But if you do this you can never use this principle in combat as it will be too slow.
If anything, you need to thread all 9 pearls at the same time or at the very least a timing that approximates nearly simultaneity. However, if you try to do it with single minded concentration you will not be able to do so because you cannot focus on more than one area at a time, not unless you follow the principle of concentrating without concentrating as what Takuan explained in how the thousand hands of the Buddha can move so freely by not putting the mind anywhere and yet it is everywhere.
This is also the reason why my Taiji students find it difficult to master the 3-5 because without prolonged training they are unable to use the 3-5 in a lively manner that on the one hand must be in sequence and yet at the same time not necessarily in sequence. It may seem impossible but believing its impossible will only cause one to fail to learn. One must believe its possible and keep practicing until its really possible that at that point one can actually see, feel and believe that the principles of the Taijiquan Classics are real and not some bedtime fairy tale.
P.S. – I was right, the clip is not about concentration but balance. I googled miyoko shida and found out that the clip is a performance art called Sanddornbalance which has been around for a few years. She is not the first to do it. See two other examples below :-