WHILE DRIVING UP TO THE LEACH PAD, PICKUP TRUCK TURNED RIGHT & HIT SOME BUMPS IN THE ROAD. DRIVER BOUNCED AROUND, AND FELT LT DOOR ARM REST HIT HIS SIDE. INITIALLY THERE WAS NO PROBLEM. LOWER BACK BEGAN TO HURT & HE SAW A DR. ON DEC.10TH. INDIVIDUAL HAD STRAINED HIS BACK MUSCLE. HE WAS WEARING HIS SEAT BELT.