The best way to deal with long standing knee pain is to first, consult a doctor and make sure there is no current injury that requires treatment. Then, consider strengthening the joint area with water aerobics. Water Aerobics allows you to do a lot of bending and stretching with resistance on your joints, but not the full weight of your body. Also, if overweight, water aerobics will help you slim down and put less strain on your joints.