bild

Peng Shuai, of China, drops to her knees in pain during the semifinals of the 2014 U.S. Open tennis tournament against Caroline Wozniacki, of Denmark, Friday, Sept. 5, 2014, in New York. Peng left the court in a wheel chair and retired from the game, forfeiting it to Wozniacki. (AP Photo/Mike Groll)