EE HAD BEEN JACK HAMMERING OUT OLD PUMP BASE THEN LOADING CONCRETE INTO WHEELBARROW TO TAKE OUT OF AREA. HE WAS MOVING FULLY LOADED WHEELBARROW THE EE TRIPPED ON A PIECE OF CONCRETE CAUSING HI M TO LOSE HIS BALANCE HE DID NOT FALL HOWEVER WEIGHT OF LOAD CAUSED HIM TO STRAIN HIMSELF WHERE HE PULLED TO REGAIN HIS BALANCE.