Brad Pitt explains reason for walking with cane

(CBS) Brad Pitt has revealed the reason he has been spotted recently walking with a cane - a knee injury.

The actor told reporters at the Palm Springs Film Festival on Saturday that he injured his ACL after suffering a fall while carrying one of his children.

Pictures: Palm Springs Film Festival 2012
Pictures: Brad Pitt

"I was carrying my daughter [Vivienne] down the hill and I slipped," Pitt said, according to People magazine. "It was either her or me."

Pitt added that he won't need surgery but may need the cane for a while, according to the report.

The "Moneyball" star's partner, Angelina Jolie, also told reporters that their daughter was not hurt during the fall.

"Vivie's okay," she reportedly said. "She was absolutely fine."

Vivienne and her twin brother, Knox, 3, are the youngest of the couple's six children.