 Running reins (or western-style draw reins) are used by many trainers to teach the horse to give to rein pressure, and most horses respond by bringing the head in and lowering it.They may also provide additional control of heavy-mouthed horses, though it can also become a "crutch" that a rider becomes dependent on using at all times.English style draw reins that run over the poll have a gag bit-like action.