I snapped my back yesterday.
I was carrying kiddo and as I put him down I felt a hot/electric pain in my lower back. On both sides of my L4.
I couldn't move well after that and for the rest of the day I had to just sneak around after the baby or lie on my back. Thank goodness he can walk. I don't have to lift him up from the ground anymore. And it's enough that his feet touch the ground when I set him down somewhere.
I used a cold bag for my back and sprayed some magnesium oil on it too.
Still.... I had to take a painkiller so I could sleep right. And I had my normal stuff at night with baby: feeding and teething ;)