EMPLOYEE WAS ASSISTING COWORKERS WITH MOVE OF UPPER RAILS. HE HAD HOOKED THE COME-A-LONG ON A BOLT AND WHEN THE COME-A-LONG WAS BEING JACKED UP BY CO-WORKER, THE BELT SLIPPED OUT ALLOWING THE COME-A-LONG TO MOVE, IT STRUCK EE'S RIGHT FOREARM. AS A RESULT, HIS RIGHT ARM WAS BROKEN PLUS IT WAS CUT ON TOP OF ARM.