I have knee, ankle, and back problems. My husband has shoulder pain. Nordic walking is perfect for us. It takes pressure off joints. It relieves tension in the neck & shoulders, The bonus is that it burns 20-40% more calories than regular walking. It is also recommended for balance problems.
There is an article on Nordic walking on Spark People. You can also do an online search for "Nordic walking" to learn more & find equipment & demonstration videos.