You may know immediately after a crash that you're hurt. You may feel pain in your neck and shoulders due to soft tissue damage or joint injuries. You could have a broken bone that hurts right after the crash. Maybe you struck your head on the windshield or the steering wheel.
Maybe you walk all the way to work in the morning. Maybe you drive your car and then walk through the parking lot. Either way, you spend some amount of time as a pedestrian.