A flight attendant, who was standing in the aft galley while securing the cabin, was injured when the flight encountered turbulence during descent. According to the flight crew, there was a significant area of weather over the Florida peninsula, so they directed the flight attendants to secure the cabin early and take their seats for the remainder of the flight. While they were securing the cabin, the flight encountered an area of moderate convective turbulence lasting about 30 seconds. When the turbulence was encountered, the “B” position flight attendant was seriously injured after being thrown down and striking the aft galley floor hard. The captain was not told of any injuries at the time of the event. The flight attendant was later diagnosed with a compression fracture of the L1 vertebra spine along with other back injuries including disc herniation and cervical, thoracic, and lumbar sprain.