INJURED WAS STANDING ON LADDER PLATFORM AT THE BACK OF A CEMENT TRUCK. DRUM WAS SPINNING AT A HIGH SPEED BACKWARDS TO CLEAN OUT AND PREPARE TO UNLOAD CONCRETE. HE WAS ATTEMPTING TO HOSE OUT BA CK OF DRUM TO REMOVE OLD CONCRETE WHEN JACKET SLEEVE GOT CAUGHT BETWEEN ROTATING DRUM AND HOPPER. INJURED SHOULD BE ON RESTRICTED DUTY FOR 2 WEEKS.