Law enforcement sources tell us Sears was on her way home Monday night in WeHo when a motorcycle made a left and collided with the car ... sending the rider flying.

Emily's backseat airbag deployed and her face was bruised from the impact. We're told she's also dealing with neck, ear and shoulder pain.

Meanwhile, the motorcyclist took the worst of it -- we're told he was taken to a hospital with a possible broken leg. Cops quickly determined the rider caused the crash.