Collapsing fingers, left and right hand technique.

[Ganky]

I have heard that both right and left hand techniques should not collapse the highest joint of the finger when either pressing down or plucking respectively. (right hand - pulling the strings toward the sky rather than down into the bass)

I'm finding this fine on the left hand, as that's what I have always done, but on the right hand, to get anywhere near close to the fast speeds that I normally play at, without collapsing the fingers seems almost impossible.

Should the uncollapased technique not be used when playing very fast, or should that come over time? I know the advantages of it, a much stronger and better all round sound, but was just also wondering whether there are any long term health issues for playing fast with collapsing fingers, thanks!