Overcheck

A bearing rein, known today as an overcheck or a checkrein, is a piece of horse tack that runs from a point on the horse's back, over the head, to a bit. It is used to prevent the horse from lowering its head beyond a fixed point. A variation called a side check passes beside the ears through loops at the top of the bridle cheekpieces.

It can be attached to the surcingle of a horse harness, or to the harness saddle.

An overcheck or bearing rein shares some function with side reins, draw reins, and the de Gogue, and has the opposite function to a chambon and martingale. It can be attached to the same bit as the reins, or to a second, separate bit.

The modern overcheck is often a necessary piece of safety equipment for certain types of harness and is an aid to the driver in keeping a horse's head properly positioned.

An overcheck has a practical purpose; if a horse lowers its head too far when in harness, particularly if moving quickly, it can catch the bridle on the shafts of the carriage or wagon, risking an accident. 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. On a hard-working draft horse, it generally is not used at all, as it puts the animal off balance by preventing it from lowering its head when trying to pull significant weight. A horse pulling weight normally lowers and extends its neck in order to distribute the load. If an overcheck is inappropriately used, or used for too long a period, spinal strain resulting in neck or back injury can occur.

The overcheck is also used today in some equestrian riding activities, and for certain types of horse training. In particular, it is used on certain saddle seat horses while on the longe line as part of a bitting rig that assists the horse in learning the proper high set head position for competition that also emphasizes high knee action. While not normally used by a rider in the saddle, it is common in some places to put an overcheck on ponies when being ridden by very young riders in order to prevent the pony from putting its head down and grazing while being ridden, an act of disobedience that a small child often lacks the physical strength to prevent.

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