I wanted to also mention that we live in Oregon & the cold, rainy, foggy days tend to be worse than the warm days. He also owns his own business & is on a concrete floor a considerable part of the day. Other than work, we don't do much any more as it's just too tough on him. We used to hike, enjoy water sports & snow skiing but now we watch alot of t.v., do research on the computer, play board games & Playstation. He's pretty sick of not being able to do physical activities.