BACKING HAUL TRUCK UNDER SHOVEL- WAS JOLTED IN TRUCK BY CHUNKS BEING DROPPED IN HER TRUCK BOX- SHE FELT SUDDEN PAIN IN HER LEFT SHOULDER. SHE CONTINUED TO HAUL. AT FOLLOWING SHOVEL SHE BACK- ED INTO SHOVEL BUCKET WITH HER TRUCK, BRACED HERSELF BUT WAS THROWN AGAINST THE STEERING WHEEL. SHE EXPERIENCED STABBING PAIN IN SHOULDER.