I quite often get a back pain in the marked area, only on the right side of my body. It ususally gets ignated during deadlifts and persists for 3 to 12 days. It worsens while sitting, but I get no pain while standing etc.
I don't know why that happens, I worked on my deadlift form a lot, recorded my sets, even took lessons from powerlifters to make sure that everything is correct, and the pain gets ignited very randomly. On one day, I deadlifted 175 kg for 3 reps and everything was fine, and a week later I got fricked up again during a warm up with 140 kg. I don't know why the frick is that happening. I use mixed grip btw.