By TOM SHANAHAN My MSUings on the Michigan State (1-2) falling flat from last week’s stunning upset of Michigan. The Spartans were physical a week ago, passive in a 49-7 loss Saturday to Iowa (1-2) at Kinnick Stadium in Iowa City. DON’T TRY TO EXPLAIN IT This is only the third game of the Big Ten season, but if you look around at the other conferences that began playing September, this was a typical weekend of college football.…