EE WAS SUPERVISING A EXTRA NIGHT QUARRY PRODUCTION SHIFT. MATERIAL BRIDGED OVER THE SECONDARY SCREEN DISCHARGE CHUTE AND PLUGGED OFF THE SYSTEM.HE SHUT DOWN AND LOCKED OUT THE FEED EQUIPMENT & HIS CREW BEGAN DIGGING OUT THE CHUTE. TAKING A TURN WITH A SPUD BAR, HE FELT A SHARP PAIN IN HIS LEFT SHOULDER. INITIAL TREATMENT WAS NON-MEDICAL UNTIL PHYSICAL THERAPY WAS ORDERED 5/9/01.