Feet...Are Smelly

Sorry about the title guys...

Sophocles uses feet as a metaphor for fate.
Oedipus is bound by his destiny from the day of his birth. Instead of a celebration, he gets an incestuous prophecy that he can't avoid. His baby feet are bound by ropes as a Theban shepherd carries him to his death; this symbolizes the fate that he is bound to for the rest of his life. Feet are vital, but from his birth, Oedipus was bound and helpless and couldn't escape, just as he could not escape the fate that the prophecy spelled out.
It's also important to note Oedipus's fate as an abandoned child. His biological parents discarded him, and that becomes his true nature as he grows into a man. His injured feet reflect his injured nature and affects his gait. While Laius wanted to kill baby Oedipus right away, Jocasta couldn't do that to her own son. Because of the conflict between wanting to save her husband and wanting to save her son, she hoped to send him far away so he could at least live. Oedipus ended up with swollen ankles (thus the christening of his name) and walked abnormally for the rest of his life. This mirrors his fate as a king who is meant to go far, go places, but must suffer being stuck in the destiny that the gods have planned out.
Kneeling is also symbolic in Oedipus Rex, as people kneel when they are in surrender or are submitting to authority. The Thebans always make this motion of shifting body support from the feet to the knees when they are pleading and asking for something. This symbolizes a desire to avoid fate and the gods and wanting to submit to human control, specifically Oedipus.

Feet are obviously essential for getting around in your life. From the beginning, Oedipus must deal with his twisted and injured feet, just as he must always carry around his twisted fate.