martingale

A martingale is a piece of horse tack used in horsemanship to steady a horse's head or control its upward movement. It typically consists of a strap that connects to the girth, passes between the horse's forelegs, and then splits to attach to the reins. This device is considered an artificial aid, meaning it's a piece of equipment used to communicate with the horse, alongside natural aids like voice, hands, and legs. While not necessary for a well-schooled horse, martingales can help prevent a horse from tossing its head too high, especially near obstacles. Some martingales also feature decorative metal plaques called horse brasses, which have been used since at least the 19th century.123