
TheBearing rein also called acheck rein orovercheck, is a type ofrein attached to thebit on abridle, that runs over the head of the horse, attaching to theharness saddle or pad. The primary purpose of a bearing rein is to prevent the horse from lowering its head. The secondary purpose is to raise the horse's head to a higher position for aesthetic reasons. A bearing rein is not held in thedriver's hand and thus does not direct the horse to turn, slow down, or stop. It can be attached to the same bit as thereins used to control and direct the horse, or to a second, separate bit sometimes called abradoon.
There are several variations, but all bearing reins start by connecting to the horse'sbit or a separate smallbradoon bit, then reach to a ring or hook at the center of theharness saddle or pad, called apad hook orbolt hook. Bearing reins are optional in harness driving, however when using them the harness must have acrupper to keep the harness in position and not be pulled forward by the horse stretching against the bearing rein.[1]: 420, 451 [2]: 20, 31, 98
Overchecks are often used in conjunction with arunning martingale when driving.

A bearing rein is used primarily to keep a horse from lowering its head. It should be adjusted to keep a horse from lowering its head too far—such as to graze grass while in harness, scratch their head on their knee, or pull the reins loose from the driver's hand. The primary safety concern is the risk of a horse getting the bridle or reins caught up in the ends of ashaft orpole.[1]: 414, 450 [2]: 20 [6]: 23
The sidecheck with drop style is common with Britishcarriage driving and when training on thelonge line, while overchecks are more common in North American styles of driving such asfine harness competition.[2]: 204 The overcheck style is common inharness racing where an overcheck keeps the horse's head at a predetermined height, limits it from tucking its chin, and helps the horse maintain stride and balance.[4][5]
Driving judge Muffy Seaton stated that although overchecks are permissible or even mandated at some breed-specific horse shows in the US, "overchecks are not allowed at American Driving Society,United States Equestrian Federation orFédération Équestre Internationale sanctioned events".[7] In Canada and the US,showing infine harness driving classes (formal, pleasure, park, roadster) for the breedsSaddlebred,Arabian,Hackney,Morgan, andWelsh mostly mandate the use of overchecks with some giving options for sidechecks, while mostperformance competitions such as drivendressage, obstacle classes, andcombined driving prohibit overchecks and sidechecks.[8][9]
According to Shaw (1909), the purpose of the bearing rein is to "assist the driver in controlling the puller or horse that is liable to stumble" but because it also "causes its wearer to carry his head better, it is often utilised for the purpose of improving his appearance".[6]: 23
Fairman Rogers wrote in 1899 that the use of bearing reins had mostly been discarded forcoach work, but remained in vogue for park driving in order to have a uniform position of the heads of an entire team of horses. He allowed that they were acceptable if adjusted intelligently, suggesting they should be slightly slack while the horse was in motion, and would likely be taut when the horse was standing still. For work which might include going uphill or with a heavy load, "a horse throws his weight forward into the collar and puts down his head", and therefore would be hindered by a bearing rein. Rogers goes on to note that bearing reins can help to control horses in the excitement of a parade, or to save acoachman from fatigue of a horse which bears down on the bit—for which he recommends changing a horse's bit and training him not to pull on the driver. He also suggests it might discourage a horse inclined to kick because it must first get its head down. Rogers considers the overcheck style "an instrument of torture", only allegedly useful to raise the head and open the airways for a racing trotter. A final caveat from Rogers: "If bearing-reins are not used, the coachman must always keep his eye on his wheelers when they are standing still, or one of them may drop his head and, getting his bit caught on the pole-head, pull off his bridle. For this reason the bearing-rein is not out of place on a pair used for shopping or visiting, but it should be loose."[10]: 256–263

Properly adjusted and when used for a limited period of time, an overcheck does not significantly impede the motion of the horse or cause discomfort. If too tight, however, an overcheck rein can be uncomfortable because it puts strain on the neck muscles and ligaments. If an overcheck is inappropriately used, or used for too long a period, spinal strain may result in neck or back injuries.
In the 1800s, overchecks and bearing reins were often used on stylishcarriage horses to keep their heads up, at times to an extreme degree, depending on the fashion of the time. Improper use and overuse created chronic problems with the spine and back that in some cases made certain horses useless asworking animals. Fashion extremes tightened bearing reins to the degree that it made breathing difficult.
Tight bearing reins were even thought to contribute to the onset of whistling and roaring.[6]: 278, 358
The Anti-Bearing-Rein Association was founded in England by a "Mr. Allen" to try to stop the practice of using bearing reins abusively,[11] and it published pamphlets illustrating anatomically how bearing reins negatively affected the airways, cartilage and ligaments of the horse's neck and gullet areas.[12][13][14] In 1875,Edward Fordham Flower published his book titledBits and Bearing-reins in which he describes driving with such contraptions a "barbarous custom"; the book was published seven times.[15][16] The 1877 novelBlack Beauty portrayed the abuses of bearing reins and Joan Gilbert remarked that "under the influence ofBlack Beauty ... the bearing rein went out of style".[17][18] The cause was also taken up by the Canadian Society for the Prevention of Cruelty to Animals.[19] By 1893, the overcheck had been outlawed in several US states.[20]
The termbearing rein is derived from the definition of "bearing" which means "the manner in which one bears or conducts one's self; mien; behavior; carriage." The reference suggested that high head carriage was a sign of nobility or pride. However, 19th century critics of the bearing rein applied a pejorative meaning to the word, meaning "patient endurance; suffering without complaint".[citation needed]

A bearing rein or overcheck is rarely used whileriding, however occasionally agrazing overcheck is used when a small child lacks the strength to stop a disobedient pony from reaching for grass while being ridden.
Side reins are auxiliary reins used in training andlongeing, but not for driving. The reins run from the bit to asurcingle,girth, or riding saddle. They are used to modify head carriage or encourage a young horse to have contact with a bit.[21]: 440 [22]: 194 Somesaddle seat breeds use an overcheck withside reins as part of abitting rig to teach the horse the proper high head position for competition.
Other types of training equipment that pass over the horse's head include thechambon, and theGogue, though these are used to lower the head, not raise it.