OMG!!!!!!!!!!! Alyssa gave me the scares today!!!!

So like Alyssa was in her ball for a lil bit today, then she ran around the couch eating treats and everything was fine, I put her back in her cage and did some stuff around the house, checked on her then left the house for about 3 hours to run some arrends.
When I came home I emediatly checked on Alyssa... normaly she would be sleeping, greeting me or nibbling at her food, except this time she was just sitting there cruched over with her back looking funny.... I freaked!! I thought there was something wrong, I took her out of her cage and her back was like a hump... umm idk how else to put it, but it didnt look normal.
at first I thought it wa broken but she didnt seem like she was in any pain.. I held her by the scruff of her neck and usually her back would straiten but it didnt.. it just kept its humped shape.. worried, I put her back in her cage and sorta left her there ((i know it sound lame)) I just didnt know what to do and the vets wasnt on the list ((sorry if that sounds mean)).
Well I checked on her about an hour and a half ago and her back was normal again... have any clues on what it was or what happend??