I think my knee can predict the weather!
A few years ago, I tore my ACL. Not in some dramatic way, such as skiing down a slope in a whoosh of snow or leaping high over defenders to make a dramatic slam before crashing to the basketball court.
No, I was just hiking at the Delicate Arch in Utah and felt a pop as I was stepping down from a higher trail to a lower trail. Not dramatic, but every bit as painful. My orthopedic doctor tells me most of his patients tear their ACLs in pretty routine ways and not necessarily playing sports. That helped, a little.
UNC-TV Science Week In Review: October 31, 2013