[GenuineRisk]

The elliptical trainer machine might be an option for you, too. Much easier on the knees than running ot walking, and it works the arms, too.

I'd also suggest looking into a Pilates class if any are offered in your area-- it focuses on strengthening the stomach muscles, which helps ease back pain.

Losing weight may actually help relieve your joint pain, too, making walking easier-- extra weight is extra stress on the joints.

Ditto on getting your doctor to give you a specific diet/exercise plan, or get him/her to refer you to a nutritionist for help setting up a specific plan for you.