Hi,
Sorry about getting back to you so late. I've been on vacation.

You ask a very unique question and I'm afraid I don't have a good answer! I'm not aware of any device that would help with mobility of the front legs.

Why are her legs "contractured"? Is it because of a bone, joint or muscle problem? If you haven't consulted with an orthopedic specialist, then I would do that next. You should consider going to a veterinary teaching hospital (at a university) where they love those kind of specialized problems and you can get lots of input.

Good luck
drphilvegasvet

Have you tried some of the dog cart companies. They make carts for front leg support. Try k9 carts, Doggon Wheels, Eddie's Wheels. They may be able to help you.