ORLY!?!
Master Loader
This explains the part-timers I knew who had been around 15-20 years (back in '02) but never went driving. Didn't understand why they didn't want the significant bump on pay (most of em had it! But I think they all have retired now).
And ORLY! Loaders work harder, but being a Service Provider is the hardest non-management position. Drivers work hard, too, but in addition deal with the public, time deadlines, and numerous other demands. You'll walk and lift more as a preloader, but the hardest thing about it is it is a thankless job (ya'll should have loaded pre-PAS, when you had to memoroze the load chart; the level of skill involved on loading [and sorting] is why those positions make a dollar more).
I am sure the responsibility of service provider makes the job very hard. I was just talking to a driver today who always seems to get the helper that doesnt get the COD check or sig or release. Thus falling upon him in punishment. That he has to always look out for such things, closed times and drop areas. Its a lot to know and do.
Preload is just hard on the body and the mind. Run threw the gambit of things that destory our bodies as much as drivers. I'd say they are similar in difficulty, thus the past interest for preloaders to drive.
As for the OP, I'd get a pair of low top brahma steal toed shoes. The black low cut ones, great comfort and feels like a walk show with the protection of steel toe. Trust me, after a few heavy ones fall on your open shoe, you'll be dieing for a pair of them.