I have had a knee replacement but then scar tissue developed and my leg is stiff as a board. Nevertheless I was able to walk while dragging the leg. Suddenly however, I cannot walk because I have no balance while standing. I can only hobble with difficulty using a walker. I have been taking ziprasidone ten years; I wonder if the ziprasidone is causing my loss of balance? I also have tremors in my hands, which I believe the ziprasidone is causing. But mostly I am very concerned with my loss of balance while standing. Has anyone experienced this?