He could walk now, thanks to Katara's abilities.
He could jump. He could run. He could dance. He could kick. He could do what normal guys do.
He looked wistfully at the petite earthbender teaching her student. A surge of adoration and despair flushed through him. The feeling of pain intruded into his chest, a familiar guest, as he spots her punch Aang hard on the arm--her way of showing affection.
He may be able to run, but compared to Aang's steady progress, he was a mere limping fool.
Prompted by the word: LIMP