The joint pain you have is not due to stroke or medicines. It is a form of arthritis. This is if the pain is only at knee and shoulder. If the entire right side is paining that is likely to be due to stroke. Recently we have found that high serum homocysteine and low Serum B12 are common in strokes in India and this is particularly so in vegetarians or occasional non veg eaters. As you have done several tests you could do serum homocysteine and serum B12 and rheumatoid arthritis (R.A.) factor test and ESR to see what type of arthritis.