The One Direction singer`s back has been causing him trouble ever since he had a paper round when he was younger and Harry, 18, has been advised by doctors to rest for a few weeks before taking up a pilates class in order to help him recover and fix the resulting bad posture.
He told The Sun newspaper: "I have bad posture and I`ve been told to takepilates once a week."
Harry`s One Direction bandmate Niall Horan has also revealed an ongoing knee problem which could put him out of action at any time.
He said: "I dislocated my knee playing football one time. When I got checked by the specialist I was told I`ve got a 67 per cent chance of walking down the street and my knee dislocating itself."
Meanwhile, the band are reportedly in talks for their own show in America after recently impressing TV bosses at Nickelodeon with their acting when they filmed a guest appearance on popular programme `iCarly`.
A source told Now magazine: "Simon [Cowell] has vowed to launch them on the US X Factor, while Nickelodeon are in talks to give them their own show."