The Other Arch Of The Hand In Piano Technique

I thought it might be good to post this clarification, prompted by a recent email from an American doctor who has my book and film. He asks, "By the way, I have a question with which I hope you can help me: I never really quite understood the SECOND arch of the hand from your book and DVD. I DO understand the other arch, the one which runs from the wrist anteriorly to the finger tips. But it is the second arch which is giving me trouble." I thought the second hand's arch would be clear to you being a doctor, because although I first conceived the idea on my own, I later found corroboration in a medical anatomy book (I forget which one). If you lay your hand flat on the table, it doesn't rest flat. In VERSION ONE of the hand's lateral arch, the thumb's metacarpal is on the table, the fifth metacarpal is also close to the table while the fourth and third slope up to the second which is highest. Thus the second metacarpal is the keystone of the hand's transverse arch in this first version. However, for the purposes of piano technique it is better to RAISE the fifth metacarpal to be more or less even with the second metacarpal. Even here there is a slight arch because metacarpals three and four are slightly higher than two and five and it is these middle two that now constitute a keystone of sorts. This is VERSION TWO of the lateral or transverse arch of the hand. In my film I show version one, but since then I have gone to cultivating version two, which works better on the keyboard (see Seymour Fink, section 12C) AFF