Basically it's a Canine Behaviourist you'd need to speak to, rather than a trainer.
You could look one up in your area (google or check yellow pages) And call your regular vet, because it's possible they may know of someone.
She may have been just lacking in confidence ever so slightly 3 months ago, then suddenly had a slip on the floor which scared her. Perhaps when jumping down from the couch....etc. You might not have even seen it. But during her 'learning about how the world works', she has somehow learned that the floor can betray her. And she is not wanting to let go of that idea.
A good behaviourist SHOULD be able to get through to her. But you are wise, as this shouldn't be allowed to carry on or she could become neurotic.
Poor little thing! I hope it's solved soon.
She is a bully pit. I had read that could be the problem so I had the trainer check out her paws & he didn't seem to think they were causing the issue. Her more recent skiddish issue with being scared entirely is getting much more concerning :(
Well, just had a whole paragraph typed and lost it!! It is late but I will try to address this tomorrow.
Briefly, what breed is this? Check the bottom of her feet. If there is a lot of long hairs protruding between the pads, get some scissors and cut the hair even and as close to the pad as you can. Hair can make the footing more slippery.