THE EE WAS USING A PNEUMATIC JACKHAMMER TO BREAK UP PRODUCT STRUCK IN A HOPPER. THE EE HAD POOR BODY POSITION WHILE PERFORMING THE TASK RESULTING IN STRAIN TO THE LOWER BACK MUSCLES. THE EE CO MPLETED HIS SHIFT & RETURNED TO WORK THE FOLLOW-ING DAY & COMPLAINED OF PAIN. HE WAS AT THIS TIME TAKEN TO THE CO. DR. WHO PLACED HIM ON LIGHT DUTY.