There are many riders who use leverage devices, which also can include not only draw reins and running reins, but also the
running martingale, to force the horse into position. However, this is incorrect usage. Misuse usually involves the rider pulling the horse's head in to achieve a "headset" rather than getting the animal correctly
on the bit. Like the equally controversial practice of
rollkur, the horse does not flex properly at the
poll, but rather flexes improperly at a lower neck vertebrae. This practice often results in a horse that is working in a "headset" or "outline" that, to the inexperienced observer appears acceptable, but the horse has no self-carriage or suppleness and does not properly engage its hindquarters. These pieces of equipment can have very detrimental effects if they are adjusted tightly, used strongly, or if used for long periods of time. Horses may become hard-mouthed and heavy, and they will begin to travel on the forehand if the rider can not keep sufficient impulsion. Additionally, many horses that are continuously or incorrectly ridden in draw or running reins may never learn to engage the hind quarters and lift their withers for self-carriage, and this habit may permanently damage their training. In extreme cases, horses may develop neck and back pain from being forced to hold an artificial position for long periods of time. The incorrect use of draw reins will produce horses who are overflexed on short necks with correspondingly flat backs and disengaged hind legs. It was this improper flexion that ruined the reputation of their inventor,
William Cavendish, 1st Duke of Newcastle-upon-Tyne. That being said, competent riders who correctly and tactfully use the draw and running reins can have success in correcting specific problems in horses that require retraining to get rid of bad habits. These are often the riders who use the equipment the least, because they can achieve correct results through good riding instead of gadgets. ==References==