According to crew statements, the flight crew briefed the flight attendants (FA) that turbulence was forecast for the flight and that they would keep them updated throughout.ÿ During the first portion of the flight, the flight encountered light turbulence and occasional moderate turbulence several times and the flight crew made public address (PA) announcements each time. Later, the flight encountered unexpected turbulence and the flight crew immediately turned on the fasten seatbelt sign and made a PA announcement.ÿ During that time, a FA was stowing a beverage cart in the aft galley, and the turbulence caused the cart to bump the FAs hand.ÿ The FA continued to perform her duties and the flight landed uneventfully. The next day, the FAs hand was painful and swollen and she was diagnosed with a broken wrist. Probable Cause: an encounter with turbulence resulting in a serious injury to a flight attendant.