SHOVELING PACKED MATERIAL FROM UNDER TUNNEL CONV. BELT USING A LONG-HANDLED ROUND-POINT SHOVEL. MATERIAL PACKED VERY TIGHTLY AND EE HAD TO USE THRUSTING MOTION & GREAT EFFORT TO DISLODGE, IN ORDER TO SHOVEL & CLEAN. DURING THRUSTING MOTION, THE PACKED MATERIAL BROKE LOOSE & CAUSED EE'S RIGHT WRIST AREA TO STRIKE THE CONVEYOR STRUCTURE. MINE SUPT. FIRST INFORMED OF ACC. 5/21.