Whatever the cause of your rabbit's hind limb weakness, it definitely requires an in-person examination by a rabbit-experienced veterinarian so that appropriate treatment can be started as soon as possible.
Traveling with a rabbit is definitely no small task. Quite a bit of preparation and consideration is needed, especially if you do not have rabbit supplies at the destination.
Alternative therapies can be very useful in treating rabbits for many acute and chronic conditions. The modalities work best when utilized in combination with traditional veterinary therapies.
Richard Kelly's indie film Donnie Darko may baffle rabbit-loving folk. Its monster rabbit, Frank, is unbelievably ugly. And the film hints that his rabbit-soul may be even worse than his looks.