EMPLOYEE WAS GREASING A LOADER WITH AN AIR GREASER LOCATED AT THE EQUIPMENT SHOP. THERE WERE SOME SHEEL CHOCKS AND A FEW STONES ON THE GROUND BETWEEN THE LOADER AND THE SHOP WALL. THE EMPLOYEE WAS WALKING BETWEEN THE LOADER AND THE SHOP WHEN HE TRIPPED OVER ONE OF THE STONES OR WHEEL CHOCKS AND FELL TO THE GROUND DISLOCATING HIS LEFT SHOULDER. HE WAS TAKEN TO THE HOSPITAL.