THE MEPLOYEE WAS SEATED IN THE PASSENGER SEAT OF A PICKUP TRUCK WHEN A SUPERVISOR BACKED INTO AN OUTRIGGER OF A PARKED ROOF BOLTER. THE EMPLOYEEWAS WEARING HIS HARD HAT, HE STRUCK HIS HEAD ON ROOF OF CAB. HE FELT THAT HE WAS NOT INJURED AT THE TIME, BUT AT THE END OF THE SHIFT HIS NECK AND BACK HAD STIFFENED UP.