The six-time Olympic gold medallist posted on Twitter that in addition to her back hurting, she was in pain Sunday night from "all the ribs I broke."
Van Dyken-Rouen's family initially said she severed her spine at the T11 vertebrae in the June 6 crash, but did not mention the broken ribs.
The 41-year-old swimmer was injured when she flew over a drop-off after hitting a curb on an ATV. She had no feeling in her legs and feet after the accident and said on Friday that she's still paralyzed.
Van Dyken-Rouen left the ICU on Sunday and plans to rehabilitate at a Denver-area hospital.