Kenny, a two-time Olympic omnium champion, who also took gold in the omnium at London 2012 and Rio de Janiero, as well as the team pursuit at both Games, went down just before the start of the 30th and final lap of the scratch race.
The 27-year-old, also twice a world omnium champion, had just returned to competition after suffering a broken shoulder in a World Cup event in Canada.
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Her shoulder appeared to be undamaged as she was treated by British team doctors at track-side but she had suffered a nasty gash to the right of her eye.
British team officials said they would give an update on her injuries, and confirmed shortly afterwards that she was back on her feet. Other riders appeared to be injured, according to tweets from inside the venue.
She later competed in the other three events of the discipline, which was won by Japan's Yumi Kajihara.
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