Reliable Source: Why is Sonia Sotomayor wearing a cast?

Close watchers of the Supreme Court typically pore over every move the justices make from the bench, looking for clues about how the opposing sides' arguments are going over. So that blue cast encasing Sonia Sotomayor's right hand Monday might have thrown them for a bit of a loop. (Why was it blue? Why the right hand? What does it all meeean?)