MARK WAS OPERATING THE AUTO SACKING SYSTEM AND HAVING TROUBLE WITH THE BAG SEALS. MARK WAS STACKING THE UNSEALED BAGS INTO A PILE. MARK BEGAN TO WALK OVER TO THE AUTO SACKER CONTROL PANEL AND CAUGHT HIS LEFT FOOT ON A BAG. HE TRIPPED BUT WAS ABLE TO CATCH HIS BALANCE. LEFT HIP WAS SORE.