I had a thread about my mare few months ago, asking why she sometimes stands like this while grazing on steep hills.
She is doing this since I know her. Vet said not to worry about it, but he didn't even check her, he only listened to my description and asked if she has any lameness problems.
Anyway, lately she started standing like this on flat too, or when she's resting in the stall. She doesn't prefer any leg, she's not lame, she's not hesistant to move, she doesn't do it all the time, only when she's resting or grazing without moving for few minutes, she works with the same energy as always (and that's a lot of energy :P), she doesn't care if I push anywhere on her back, hips, legs, I don't find any swollen or warmer part.
I'm wondering if the hunter's bump could be the reason? And why she started to stand like this more often?