Digging for clams is hard.
First you look for the “clam shows” – the air holes in the sand that show where a clam might be. Once you find a nice, big hole, you dig the wet, heavy sand around it, pushing your shovel as deep as you can. Then you bend, squat, or kneel to look through the pile of sand you just turned over, or plunge your hand in the hole feeling for clam shells. And then you stand up again, and move to dig in another place.
Dig. Squat. Stand up. Repeat.