I adopted Merida in early February; during the first two months or so that I had her, she would occasionally do these strange stretches where she pushes her pelvis down towards the floor (see pictures below). They only lasted for a moment, like more normal/common bunny stretches do. (Thus the poor quality of the photos; I had to zoom in and take them quickly with my phone camera before she finished.)
Once she did these stretches while licking my hand, so I figured she wasn’t in pain, but another time I saw her tense a back foot and spread her toes, almost like she had a cramp, so I’m not sure that they were always pain-free.
I did take her for a check-up when I noticed she was doing them every few days; she passed her physical with flying colors. No bloodwork was done, but I did have x-rays taken to soothe my neuroses and there was nothing besides a few small bubbles of gas on their way out.
The weird “yoga” stretches are much less common now (possibly because I stopped giving her yogurt treats as soon as I realized they were no good for her?), and she continues to be a normal, happy, healthy bunny in every other way, so I don’t worry too much… Basically I’m wondering if anyone else has seen a rabbit stretch like this?
notice the chest off the floor and the pelvis down

a more normal, if somewhat hunched, position immediately after the “yoga” sequence was completed