Singer Katy Perry is suffering from chronic knee pain and has taken to having acupuncture three times a week in a bid to save her ailing joints.

The 30-year-old, who performed her ballad "By the grace of god" at the Grammy Awards Feb 8, said her constant performing has taken its toll on her body, reports femalefirst.co.uk.

"My knees are giving out on me now. I do acupuncture every two or three days," The Sun newspaper quoted Perry as saying.

She added: "I tour with a stage that goes from the front of the house to the back of the house with a triangle thrust that is a moving treadmill, like I think I'm some kind of Olympic athlete."