One Direction star Niall Horan has opened up on his knee condition, revealing that he has a high chance of dislocation just by walking down the street.

The Irishman was recently seen on crutches and it was said that he had an operation on his knee.

Speaking to the Mirror, Horan said that he dislocated his knee when younger and that it has a high chance of occurring again. He said:

"I dislocated my knee playing football one time and when I got checked by the specialist I was told I've got a 67% chance of walking down the street and my knee dislocating itself."

Bandmate Harry Styles meanwhile told the newspaper that he does Pilates in order to straighten out his posture. He said:

"I have bad posture and been told to take Pilates once a week. I'm working on it. I think it was linked to my paper round as a kid."

One Direction meanwhile are due to release their second album 'Take Me Home' on November 12.