If it's true that no nerve damage is showing up on your left side, where you have the radicular pain, then something is irritating that nerve (sounds like L5-S1, having been there myself), there are still a few things to do.

First, you could find a pain guy who needles. Even with a normal MRI, if you're having such specific pain, I'm pretty sure a pain guy would want to give you a transforaminal epidural. First, they shoot a bit of saline on the nerve, and if it gives you the same pain you're complaining of, they've got it. Then the epidural calms the inflamed nerve down.

That's just about the left leg.

Another approach to the left would be a different form of physical therapy. I found feldenkrais to be amazing. It's a mind/body integration thing, and the therapist essentially moves your muscles in patterns that are efficient for use, but pain-free, and re-patterns the way the brain moves you, so you avoid pain. I've been sustained by feldenkrais for over a year now. Given my MRI, I should be in agony and I'm not.

In terms of the burning feet---I'm not at all sure this means you have PN. While it is a symptom, typically we get other sensations with the burning---numbness, tingling, electric pain, wormy feelings. You just have burning. That could be mechanical from you back.

Sometimes I get into problems with my feet. My feldenkrais worker watches me walk down the hallway and has me report my sensations, so I grow more aware. Invariably, when my feet are bothering me, it's because I'm landing hard on them, and my center of gravity is not gliding over them smoothly. That's not something I can fix on my own, although I can approach that. It is something she can fix, however, by doing things like moving my feet, and then hips and more, in the movements they need to make to have my center of gravity glide over my feet, not land like a thump.

You might google it. I know it sounds like mumbo-jumbo, but it's not.

I understand it's a real problem being a worker's compensation case. Worker's comp pays doctors less than insurance does, so you get them putting in less time, and also being a bit cynical. Is there a way to drop the compensation claim and use your regular insurer? That might get you better doctors.

I think your problems sound mechanical and anatomical, with irritated inflamed nerves, and skewed posture and movement from years of back trouble. That's just my guess.

Hope this helps. Best of luck.