LOOSE ROCK BEHIND 6'X9'X4""WELDED WIRE PANELS IN THE DRIFT BACK WAS BEING RELOADED. MEN WERE WORKING FROM A MAN DECK WITH A GUARD RAIL. A ROCK FELL THRU THE CUT OPENING IN THE WIRE AND BOUNCED OFF THE RAIL POST STRIKING THE MINER BEHIND THE STEEL TOE ON THE R FOOT CAUSING A LACERATION REQUIRING 5 STITCHES.