Sorry, I didn't realise that was unclear. By "back" and "forwards", I mean movement through the flow of text relative to the cursor position. Given any reference point in linear text, all surrounding content either precedes or follows that point. Moving through preceding content is "going back", and moving through following content is "going forwards". When we move to the preceding line (↑) or preceding character (←), we're going "back". When we move to the following line (↓) or following character (→), we're moving "forwards". My point was that ← ↓ ↑ → effectively represents "back one character — forward one line — back one line — forward one character", which feels counter-intuitive to me.

> strongest finger, the index finger.

Interesting. As far as I now, middle finger is usually considered stronger than the index finger. Index finger might be more dextrous, though (?). Personally, I also slightly prefer the middle finger for rapid pressing over the index finger, but cannot see strong definitive advantage of either one. (I guess most of us use the middle finger for regular ↑↓ keys, as well as W/S in WASD bindings in games/project just fine, and using index finger in that context instead would feel odd.)

> what is your neutral finger position?

Mostly index finger on "K". (So I guess I'd prefer having "down" (being the most frequently used when VIM binding is involved) on "L", where my middle finger usually dwells, and "K" for moving up, if I had to invent it from scratch.)