My small 12 pound terrier/chihuahua mix has suddenly (in the past 24 hours) stopped jumping up on things – couch, chair, etc – which is very unusual because she prefers to be on the furniture. She will stand and stare at the couch and seem like she’s going to jump, she even starts to a bit, but then she won’t follow through. If I pick her up and put her on the couch, she will not hesitate at all to jump down when she’s ready. She will let me touch and move all of her legs and has not vocalized in pain. She walks and runs normally and will come up and down the stairs with no problem. I assume she has injured something. Is there an injury to a specific place that would cause her reluctance to jump up but not affect other behavior? (I should note that she is very independent and doesn’t like to be picked up, so it’s not that she’s preferring to be lifted up)