Degenerative findings in back

I just had an MRI on my back and the findings are mostly degenerative-

Findings: Mild to moderate multilevel lumbar spondylosis (notable L4-L5) Mild spinal canal stenosis Moderate bilateral foraminal narrowing Right lateral recess narrowing → impingement of right L5 descending nerve

The impingement on the right L5 nerve is where most of my symptoms are coming from. I never had back problems before. I'm a housekeeper at a hospital and hurt my back string mopping after they switched the department I cleaned. Before I just used flat mops. I TOLD them that string mopping was to strenuous for me but they insisted I do it anyway. I hurt my back within a week of doing it.

I still am waiting for my appointment with ortho on Monday. What are the chances WC claims it's a pretty existing condition and reduce benefits or deny treatment? So far everything's run smoothly and I haven't gotten a lawyer. If they do claim that should I get a lawer? Anyone have this happen to them? I'm really concerned.