IE was following the shear to the HG straightening the pan. IE stopped to wait on the srb to catch up. IE's position was at shield 35 on the longwall face. IE put a hand on the handrail and a rock fell from in between the shields and hit IE's left hand. Shields were set and not in motion. Rock measured 6""x8"" and was 1""thick. IE was diagnosed with a swollen hand.