With the release of Chrome 52, the backspace button no longer navigates back when pressing it. Highly annoying, because the navigating back with the backspace button is just very, very handy (it only requires one finger/hand!).
“Go Back With Backspace” is the official Google released Chrome Extension that restores this behavior (other – non-Google developed – extensions have been around before).
This extension re-enables the backspace key as a back navigation button — except if you’re writing text.
In case you want to know: here it’s PINKIE+MIDDLE+INDEX+THUMB. Lately I’ve been using RING+MIDDLE+INDEX and the S with the right hand INDEX/MIDDLE more often as that’s less stressful/more natural on the fingers.