When I was a little kid, I used to play piano. Of those time only few things are left: I don’t rest my wrists when using keyboard. Most of the time my elbows are also in the air, but that depends on the table and chair having right heights.
I prefer when keyboard upper rows are higher then the lower ones - that makes it easier for me to reach them.
And I lift my right hand theatrically after hitting an enter key 
Despite of two decades of mouse-clicking and keyboard typing I have not developed any wrist or elbows problems :). Pianists do have their keyboard use system well thought out.