Everyday Systems

I decided that I wanted a more natural analog to hit the biceps. So, I'm pretending I'm doing this:

I'm in a tunnel, moving dirt from the solid wall of dirt in front of me to a cart that's immediately behind me. I attack with the shovel, then toss the dirt hard (it's the hard toss that's like a curling motion) over one shoulder into the cart behind me (right hand forward over the right shoulder, then left over left). I vary the height of the "attack" from chest high to ground height. 50 with each arm forward.

This seems to hit the biceps pretty hard.

So you are doing the basic shovelling motion, but higher up?

Higher up, to lower down, just as if I was trying to tunnel forward: it's bringing the head up and over your shoulder quickly - without twisting your body - like you were tryng to throw the dirt off the shovel immediately over your shoulder. I guess you could also look at it as being in a shoulder height hole and wanting to clear the edge of the hole with the dirt.