With stenography, you do transfer much of the "push" to your forearms (and keeping the wrist reasonably still). You just place your fingers in the right position for the keys you want. It's unlike typing where you use the force of your fingers to actuate the keys.

The primary goal of steno though isn't to provide chords - it's to learn a short-hand language enough to reduce whole words or sentences down to a single stroke of the arm - so you can get down much more information with less movement.