Happy birthday Clock!
Hope your knee feels better soon. +1 on Chi Running, if you decide you want to continue. Hopefully they've given you plenty of new core and hip exercises to help with that SI joint.
"I felt [the women's Olympic marathon] was as important as women having the right to vote, because talent, strength, and capability cannot be fully realized if there are no personal rights to allow them to be visible or be deemed significant in the first place." - Kathrine Switzer, Marathon Woman