GROUND CONDITIONS WERE WET FROM EARLIER RAINS. EE WAS RE-MOUNTING THE HAUL UNTIL USING 3 PTS OF CONTROL RULE WHEN HIS LEFT FOOT SLIPPED WHILE STEPPING WITH THIS RIGHT FOOT RESULTING INT HE EE CATCHING HIMSELF WITH BOTH ARMS. NO IMMDIATE INDICATING OF A PROBLEM PHYSICALLY UNTIL APPROX 30 MIN. LATER WHEN DISCOMFORT INCREASE. EE ASKED TO LEAVE AND GET IT CHECK WITH NO ASSISTANCE NEEDE