I Have A Relative Who Is Having Trouble Walking. She

I have a relative who is having trouble walking. She has had several MRIs with no problems diagnosed except arthritis. She has been taking prednizone to fight the arthritis. The prednizone is almost finished and she has had limited improvement as a result of the doctor's prescription. Are there any other drugs that can be prescribed to fight the arthritis? She also is going to physical therapy. Can physical therapy help with the arthritis problem?