and is not a suggestion. It may seem off topic but is it?

I'm sure most of you have heard how people with arthrius or an old wound will say, "There must be bad weather coming. My hands, knees," or some other mechanism that aids us to ambulate, "hurts!" and bad weather does descend.

Doctors will disclaim that the weather is not a factor in this phenomenon. Those of us who experience it, know better.

So, my question is: How does a body joint become a barometer?