THE INJURED WAS INSTALLING 6'LONG RESIN BOLTS DURING NORMAL BOLTING OPERATION. DUE TO THE 5' SEAM HEIGHT THE BOLTS HAVE TO BEEN FOR INSTALLATION. WHEN THE INJURED WAS IN THE PROCESS OF STRA IGHTENING A BOLT DURING INSTALLATION HE EXPERIENCED PAIN IN LT. SHOULDER. THIS IS A REOCCURENCE TO A PREVIOUS INJURY DATED 9-6-01. THE INJURED RETURNED TO WORK ON 12-19-01 COMPLAINING OF PAIN.