Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 130; Flight Crew Type 9400
Flight Deck / Cabin / Aircraft Event Illness / Injury; Inflight Event / Encounter Wake Vortex Encounter; Inflight Event / Encounter Weather / Turbulence
General Physical Injury / Incapacitation
Environment - Non Weather Related
On our descent into LAS; out [of] FL240 we encountered a short pocket of moderate chop; maybe light turbulence. It didn't last more than a second; maybe two. Before we started down; I asked for ride reports into LAS. ATC replied 'no adverse reports on the descent.' We just left the thunderstorms in the LA area; and even though LAS had high clouds; you could see clear all the way into the airport. The turbulence came out of nowhere; it might have been someone's wake. The C Flight Attendant called; and told us that the B Flight Attendant got injured; she was sitting in the cabin; and she was going to stay there for arrival. The C Flight Attendant was going to take her position (on the jump seat). She didn't require medical attention. Because that injury prevented her from performing her duties; I decided to call the EMT's so they could make sure that she was ok. Truly; the only thing that could've prevented this was having the Flight Attendants sit throughout the whole flight. But there were no reports of turbulence on the descent. The flight through the desert was smooth. They sat through the departure part of the flight; and got up when it got smooth. There was not a single piece of information to have them sitting down.
B737 NG Captain reported a Flight Attendant was injured during an encounter with turbulence; possibly wake-related; on descent into LAS.