My Staffordshire Bull Terrior has started limping after walk.Its one of her back legs.Could it be muscular or more serious?She has been doing it for about 2 weeks now but it seems to relax after abouit aday or so...any surgestions?

I would suggest that you pop her to the vets just to be on the safe side.
Keep the walks down to a minimum and allow her to rest. If she's pulled something, walking her is just going to aggrevate the problem.

Our staffie does this too but he is an old boy and it could be the sign of arthritis plus he is overweight. I would take her to get checked out, but take it easy for a couple of days as staffies run around like nutters if given the chance.