[Frostback2005]

Muscle stiffness and lack of function, including pain associated with physical activity in sedentary people can be due to atheroscleroses in the extremities of inactive people. The pain, the weakness and the stiuffness are caused by lack of oxygen in affected tissues. It is, to some extent reversable if not too far gone, you can regrow new blood vessels to the affected regions. However, if it is too far gone, it is not reversable. You will go from a walker to a fancy chair that is provided at no charge to you, thanks to the US taxpayer!

These are the same sorts of lesions in blood vessels that cause most heart attacks. When you watch a commercial talking about how some remedy prevents platelets from "sticking", look at the underlying lesion, the atherosclerosis. These things are the real issue here, and they happen all the time in your extemities (or so they say, my wife is the real expert here...but she is not here at the moment). If you are active, you will pretty much have a functional system for maintaining blood supply to the extremities, but if you get too sedentary, they more ot less shut down, and if they get really bad, you lose the ability to regrow blood vessels in certain parts of the extremities.

So staying active is really important!