[vemv]

Lifting your arms doesn't mean keeping them in a static position. They are lifted when you're typing; else they lean on your legs (much better than using some kind of cushion/surface, since your legs don't compress your wrists). Also, one can vary the arms' angle/etc during the day.

The bad part about wrist/arm rests is - very likely they compress various layers of your body, and they force you to contort your wrists to type (because you want to reach the keyboard while some other part of your body is stuck 'resting').

[tjoff]

Maybe I overestimate how much I use the keyboard but I still see hours on straight where I would not want to move my hands away from the keyboard. You don't need to reach for the keyboard due to supports, you are resting on the home row.

Yes, movement is important and one should take breaks but that is something one should do regardless of posture. I see how lifting hands can improve that but it has to be balanced against the negatives.

If moving a hand to use the mouse is seen as a big pain point I have a hard time to see how one would rest unused hands on the legs? Underneath the table?

[deno]

When you bend your arms at 90° where are your palms? With proper posture/keyboard height they should be over the keyboard. If you’re sitting straight it’s natural to bring your keyboard to the edge of the desk. But if you prefer to be under the desk then just rest on the desk.

I made a really quick sketch some time ago maybe it helps: http://svgur.com/s/7e6

That wrist angle on the green dude is very exaggerated, the point was to show that the fingers are in their natural positions, rather than curled, which is what happens when your wrists are glued.

EDIT: Also just look where the piano lady is resting her hands.