I have to disagree about the vertical rotation - my grinder has the handle on top, spins horizontally and I find that I effectively use both hands when I'm grinding - right hand turns the handle and the left hand moves sympathetically. Hard to explain, but if you look from on top you'd see the hands crossing and uncrossing as I grind the beans.
With the handle affixed a la Handground, the non-handle-turning-hand (technical term there) can only serve to resist the motion instead of assisting with it.
I have to disagree about the vertical rotation - my grinder has the handle on top, spins horizontally and I find that I effectively use both hands when I'm grinding - right hand turns the handle and the left hand moves sympathetically. Hard to explain, but if you look from on top you'd see the hands crossing and uncrossing as I grind the beans.
With the handle affixed a la Handground, the non-handle-turning-hand (technical term there) can only serve to resist the motion instead of assisting with it.