This is such a hopelessly inadequate term for this movement that I can't find a single google hit for "tuck bales". One pitches bales, one does not tuck them. But "pitch" is wrong for what I have in mind here. It's based on something I remember having seen my grandfather and uncle (actual farmers) do. The idea is, you've got these rectangular bales of hay that need to be stacked high up in the barn. To do this, you spend a fair amount of time jabbing upward with a pitchfork. That's the movement.
"Smash the ceiling" might have been a more descriptive name, but it's not quite in character. It's essentially a reverse butter churn.
Note: it helps to have really high ceilings for this, or you really might smash them.
What muscles does this hit? Oh, a bunch, like all the movements. But it feels to me like most especially the shoulders and neck.