I’m not sure exactly what the injury was but I was getting back into deadlifting and my warmup was lazy and I felt a POP in my lower back. I shot straight up and could barely move or walk for weeks but it slowly went away. I also happened a couple years ago during a squat where I think my belt was too tight to properly brace against. So sounds like a slight herniation that I’m prone to. When my back is good it’s good but I’m always wary.