As an adult, Oedipus still limps from a childhood injury to his ankles. This limp, and his very name—which means "swollen ankle," and which was given to him because of a childhood ankle injury—are clues to his own identity that Oedipus fails to notice. As such, Oedipus's ankles become symbols of his fate. His ankles, literally, are the marks of that fate.
Swollen ankles Symbol Timeline in Oedipus Rex
The timeline below shows where the symbol Swollen ankles appears in Oedipus Rex. The colored dots and icons indicate which themes are associated with that appearance.