Palm of the hand as a spinner. I was always told a spinner on a non-power steering tractor could be dangerous. For example, dropping into a gopher hole might cause the wheel to spin out of control. Also why you should not wrap your thumbs around the steering wheel.
Power steering has made that a mute point.
Back in the 80's I had a $100 1970 Impala with manual steering that someone had removed the padding from the crossbar in the steering wheel. The car was used strictly for bombing around the fields at home on the farm. We had this one field that Dad was going to work up that had got heavily rutted a few years earlier during a wet harvest. He told me to "stay the hell out of that field".
But, me being me, and watching too much Dukes of Hazard drove in the field, hammer down of course, right into one of those ruts, stopping it dead.
In a millisecond the steering wheel now became a spinning mower blade, broke 3 fingers and thumb on my right hand, and the thumb on my left hand.
Moral of the story: ALWAYS listen to your Dad.