Sally is a rugby player who comes to the athletic training room complaining of severe pain around her left knee.

Sally is a rugby player who comes to the athletic training room complaining of severe pain around her left knee. The pain is especially bad medially and further investigation reveals that moments before she came to the training room, an opponent fell against the lateral side of Sally's left leg. What movement may Sally's knee have been forced to perform when this happened? What do you suspect is the problem?