During a local instructional flight, the student pilot was at the flight controls during the second landing of the flight. The flight instructor reported that he began correcting the yaw rate for the student pilot in the landing flare. As the helicopter entered ground effect, the flight instructor reported that he was able to align the skids with the direction of travel, but they touched down with considerable forward momentum. During the running landing, the left skid caught rough terrain and rolled the helicopter to left. The main rotor blades impacted the terrain and stopped the helicopter from rolling over. The helicopter's pitch control linkages were substantially damaged. The flight instructor stated that there were no mechanical malfunctions or failures with the helicopter that would have precluded normal operation.