Shawn Johnson

Shawn Johnson smiles during a workout session for the CoverGirl Classic gymnastics event in Chicago on July 22, 2011. Johnson announced her retirement from competitive gymnastics on June 3, 2012, four days before the start of the U.S. championships because of repeated setbacks with her left knee, and fears she was putting her long-term health at risk by continuing with her attempts to make a second Olympic team.

Shawn Johnson of the USA in action during the Women's Artistic Gymnastics at the Nissan Gymnastics Complex during Day 10 of the XVI Pan American Games on Oct. 24, 2011, in Guadalajara, Mexico.

Shawn Johnson competes on the balance beam during the final round of the U.S. gymnastics championships in St. Paul, Minn., on Aug. 20, 2011.

Shawn Johnson poses with her gold medal on the podium for the balance beam apparatus gymnastics finals at the Beijing Olympics in Beijing on Aug. 19, 2008.

Gymnast Shawn Johnson arrives at the premiere of Summit Entertainment's "The Twilight Saga: Eclipse" during the 2010 Los Angeles Film Festival on June 24, 2010, in Los Angeles.

"Dancing with the Stars" contest winners Shawn Johnson and Mark Ballas visit "Good Morning America" at ABC Studios on May 20, 2009, in New York.

Shawn Johnson puts on her dancing shoes to waltz with Mickey Mouse at Disney's Hollywood Studios in Lake Buena Vista, Fla., on Feb. 27, 2009.

Shawn Johnson is shown here with her "Dancing with the Stars" partner Mark Ballas.

Shawn Johnson poses for photographers at the 29th Annual Salute to Women in Sports Awards Dinner at the Waldorf-Astoria in New York on Oct. 14, 2008.

Gymnast Shawn Johnson poses for a portrait during the USOC Media Summit in Chicago on April 14, 2008.

Shawn Johnson waves during a rehearsal for the final night of the Democratic National Convention at Invesco Field in Denver on Aug. 28, 2008.

Shawn Johnson shows off her medals at her welcome-home ceremony at Wells Fargo Arena in Des Moines, Iowa, on Aug. 26, 2008. Johnson left Beijing with four medals: silver medals for the floor exercise, the indivudual all-around competition and the team competition, and a gold medal on the balance beam.

Shawn Johnson of the Untied States competes in the Women's Beam Final at the National Indoor Stadium on Day 11 of the Beijing 2008 Olympic Games on Aug. 19, 2008, in Beijing, China.

From left, U.S. gymnasts Bridget Sloan, Alicia Sacramone, Samantha Peszek, Chellsie Memmel, Nastia Liukin and Shawn Johnson display their silver medals after the women's gymnastics team finals at the Beijing 2008 Olympics on Aug. 13, 2008. The girls came in second place to the Chinese team.

Gymnast Shawn Johnson poses for a portrait during the Athlete Summit at Smashbox Studios on November 13, 2007, in West Hollywood, Calif.