SAN JOSE, Calif. (AP) — McKayla Maroney was back at it Wednesday, bounding across the floor during podium training for the U.S. Olympic trials barely two weeks after a frightening fall during the national championships that left her with a concussion and a fractured nose.

The reigning world vault champion was warming up on floor before the finals in St. Louis on June 10 when she over-rotated at the end of a tumbling run and landed with a sickening thud that could be heard throughout the arena.

"My brother said he could hear the boom," Maroney said with a laugh.

The 16-year-old laid on the floor for several minutes before being taken to a hospital, where she was treated and released before the end of the competition, even tweeting a picture of herself sitting on a hospital bed in the emergency room. She sent the picture to calm her followers thought admitted to using a filter to de-emphasize the puffy black circles underneath her eyes.

Maroney petitioned her way onto the national team so she could get a spot in the trials, capping an eventful two-plus weeks. She underwent three ImPACT tests, the same test given to NFL and NHL players to diagnose concussions, during her rehab. She was cleared to continue training and planned to compete on all four events when the women get going on Friday night.

"The very important thing was to make sure she didn't end up with a psychological scar," said U.S. women's team coordinator Martha Karolyi. "And that is absolutely not the case. She performed totally normal, did not show any hesitation with any of her skills."

Dr. David Kruse, a member of the USA Gymnastics medical staff, said it was the first concussion of Maroney's career and called her recovery time "normal." She missed a week of training before returning apparently no worse for wear.

Maroney is considered on the bubble to make the five-person team and likely needs to post solid scores on both vault — where she crushed the field at worlds in Tokyo last fall — and floor.