Incident Overview
An airplane was descending through flight level 180 (FL180) when the crew was advised of reported light to moderate turbulence in the area. In response, the captain instructed passengers and flight attendants to return to their seats and fasten their seatbelts. Shortly thereafter, the airplane encountered turbulence.
Injuries
Before the flight attendant could get into her seat and restrain herself, she was injured when her back struck a seat armrest. Subsequent X-rays revealed that she had fractured a bone in her shoulder.
Sequence of Events
The aircraft was descending through FL180 when the advisory about turbulence was received. The captain promptly ordered everyone to be seated and belted. However, despite the warning, the encounter with turbulence occurred while the flight attendant was still in the process of securing herself. The impact with the armrest caused a shoulder fracture, which was later confirmed by medical imaging.
No other details about the aircraft, flight, or further circumstances have been provided in the source material.