On December 7, 1997, at 1340 central standard time, the lead flight attendant of a McDonnell Douglas DC-9-50, N774NC, operated by Northwest Airlines, was seriously injured when the airplane was pushed back from a gate. The 14 CFR Part 121 Flight 807 was being pushed back from a gate at the Memphis International Airport, Memphis, Tennessee. The intended destination was Nashville International Airport, Nashville, Tennessee. When the tug vehicle stopped, the flight attendant lost his balance and hit his head on a galley door. The flight attendant received serious injuries and was taken to a hospital. Neither of the pilots, the two other flight attendants, or 122 passengers were injured. The captain reported that the pushback was normal. When he was informed that the lead flight attendant had been injured and was complaining of dizziness and nausea, the airplane was returned to the gate. An aircraft ground handler reported that the airplane was pushed back in the normal manner. After the airplane was disconnected, he was informed that the airplane was returning to the gate due to an injured flight attendant. The flight attendant reported that as the aircraft was being pushed back, it jerked and he hit his head on a galley door. The airplane was returned to the gate where he received medical attention. The initial indication was that he had received a concussion and torn muscles to the neck and head.