It's not even dragging branches. It's the repetition. It's all easy to do once. The punishment comes in when you're doing it over and over.
Routine stuff today. I went to the farm to split wood, but I tweaked my back a bit running Old Smoky. Wood was filthy, and I had to sharpen it three times on not too many rounds. Also, the choke lever fell off the carb again, so I had to take the top cover off to stop the saw. The cutoff switch doesn't work anymore. That's a hassle cause it's screwed down. The two best saw innovations are side tension screws, and quick release covers. Old Smoky has neither :^/
I only split and loaded a wheelbarrow of wood. My back's sore, and I didn't want to make it worse. It hurts, but not nearly as bad as it can get.