Aside from that any attempt to describe it has an even deeper problem in that technique is a quale. Movements as they appear can be described and communicated in words to another player but the internal sensations cannot.
It is possible, even probable, that two players' movements look identical while their internal perceptions and consequent sounds are wildly different.
So aside from obvious and gross generalisations, no, I have not found books useful. However, neither have I found teachers useful for physical technique so what do I know I suppose; I might just be peculiar.
A simpler explanation in my case would be that I have not understood what the players who wrote the books were trying to communicate, or imagined an incorrect version for myself. I know I diligently tried most suggestions in several books and rejected them because I felt they caused me to play badly.
The books are still here, unread for the last thirty years. I might read them again now out of curiosity and see what my reactions are.
2. The teacher may be describing what it feels like to make a movement rather than what's actually happening (e.g. "keep your fingers completely passive, the sound comes through the arm" even though you can see perfectly well that the teacher's fingers are not, in fact, completely passive.
Haha yes, I have experienced this too, and have problems with technique that says that things are done with the arm. I seem to be too literal to fill in the finger movements myself unless explicitly instructed to do so. For all the talk modern technique seems to focus on the arms, I do the best when I let go of thinking about them for the most part, and focus on using my hands instead.
I did not mean to say that the arms (and back, and posture, etc) are not very important, they are, only that the claim that, in a certain passage, the fingers were completely passive was an exaggeration, and that I wasted a bit of time trying to do what my teacher said rather than what she (I suppose) actually meant.
If I may ask, which books are these? If you read any of the same books I did, I would be interested in hearing your persepctive on them!
I have only three left now, those by Matthay, Neuhaus and Gat. Either the Matthay was wrongly expressed or I misunderstood it as nothing positive came from that one. Neuhaus’s seemed to be mostly a rant about his musical philosophy and how good he thought Richter was. Gat’s book suggested that flexing straight rather than curved fingers better facilitated movement from the knuckle joint, a fact I verified for myself and have used to some extent ever since. As I was primarily interested in types of music and playing seemingly unknown to these three men I grew to regard their books as irrelevant to my personal direction. The fault if such exists probably lies with me but there isn’t much I can do about it.
For the matter of learning to play an instrument they are just not that useful and the time could be better spent training your skills on the piano. When I come across people who have pain in piano playing I usually always find they are playing music which is simply too demanding for them. If skills are built up appropriately you don't come across finger breaking pieces which hurt you for long, they usually can be made gentle in your hands if your technique is capable. Of course you could have been playing something totally calm and still experienced pain, but I don't feel that was the case unless I'm wrong.Many people must learn these difficult pieces because they are trying to prove something or compete with someone or some even unfortunately have a reckless teacher, this is just not a good relationship to have with your piano studies. If you treat your relationship with the piano with a sort of humbled respect and refuse to allow yourself to play with tension that cannot be effectively solved, you can build your skills up to make even the most complicated piece gentle to your fingers. The step back may not even be that large or long before you can return to the problem. There is little use to try to make something gentle which is breaking your hands and hurting you already. The increments of improvement still will contain stubborn tension and it will still be a painful experience. You may be lucky and only a small correction will bring large relief but I would think that with a lot of experimentation already if that was the case you probably would have discovered it. Certainly reading a book will have little chance of correcting a specific problem for a specific hand with a specific piece, a good teacher is very helpful for that.Did you end up solving your pain problem?
I've found that getting in a dreamlike state while playing (for me, while improvising) where you basically aren't judging yourself at all, is extremely useful when it comes to figuring out how to play without tension. Once you get out of that zone, you take the insights gained and try to store them in memory for future use. I think mental and physical tension are to an extent closely linked. Although it's possible to play mentally relaxed but still physically tense, I'm not sure if it's possible to do the converse.