back of the left knee - very hilly course (Bluffwoods, MO CA - NE of Atchison) - heard a pop, then next steps were mildly painful - definitely no wise to continue 2 more hours on a 3-hr score course.
Dr Rob Jones said it's a strain on the left calf muscle - another part
ART (active release technique - deep massage) helped with recovery. Can run without pain or any dull ache - unlike the right hamstring which still has problems after 68 days. But not ready to go longer distances yet, but no pain any more.