EMPLOYEE WAS LIFTING 4 SECTION OF 8"" PLASTIC PIPE, WHEN ANOTHER EMPLOYEE QUICKLY PICKED UP THE OTHER END CAUSING EXCESSIVE WEIGHT TO SHIFT ONTO THE INJURED EMPLOYEE. THE WEIGHT SHIFT CAUSED HIM TO STRAIN TO HOLD THE PIPE, CAUSING PAIN IN HIS LOWER BACK. EMPLOYEE WAS SEEN BY AN ORTHOPEDIC DOCTOR, AND WAS DIAGNOSED WITH MILD BACK SPRAIN. HAS FOLLOW UP APPT ON JAN 2, 2002.