Wang treading carefully with injury 'time bomb'

Wang Qiang has revealed she was troubled by a nagging waist injury during her superb run to the quarterfinals of the US Open.

The injury forced China's No 1 to withdraw from this week's Zhengzhou Open, but she still attended the tournament's promotional event on Sunday in the Henan province capital.

"The waist injury is just like a time bomb, and I don't know when it will explode," said Wang.