Farmer's Walk/Static Hold with barbell behind back?

Question in title - tried looking stuff up already and didn't really find much in regards to the whole behind the back thing.

Any thoughts, comments, suggestions, advice?

----------- *Editing in one of my comments:

I want to do farmer's walks at home for grip/forearms, I only have access to a barbell. I don't want to do them in front of me because I feel like it's going to mess up my posture even more than it already is due to the weight being in front of me, as I'll be forced to lean forward (even if I don't want to).

I'm hoping that the weight being behind me would actually help my posture since I'll be forced to lean back/develop those muscles instead. I also feel as though the walking motion may be easier with the weight not being in front of my quads.

Flawed logic? Don't know, that's why I'm here asking.

Just for clarity, my posture issues are most like anterior pelvic tilt. My head tilts forward, my shoulders are rounded and it causes a slouch. I spend a significant amount of time at the computer/sitting in a chair.