Earlier quoted context omitted.
I worked in a job that employed lots of disabled blue collar workers. It’s the joints: bad knees, bad backs. It’s not like back in the day where you get missing fingers. That’s really rare. But the steady grind of lifting, carrying, lifting, carrying, again and again destroys the joints. That’s harder to regulate away.
Hauling materials breaks your body over time. I know from experience.
IMHO, all of these can be relieved through workplace reform. In other words, manual labour doesn't have to result in a broken body. Labourers can be taught how to lift correctly. They can be given a safe environment; and they can be rotated to lots of different tasks to prevent RSI.