Can you help me understand what's going on (worker's comp)?

I’ve had a lower back/hip injury for a while, and I started a new job last week. On my first day, I aggravated the injury pretty badly when moving some files. I mentioned it to my boss just to let her know that my mobility would be limited and explained what happened. I’ve, since, put a hold on working there and am having a procedure this week to help my back.
Anyway, I got a voicemail from an insure company this morning. The lady wants to talk to me about the “incident.”
Can any of you tell me what to expect, or what they want? I just don’t know what’s going on…