A good rider with a correctly trained horse will not usually need any auxiliary reins at all. In many situations, however, auxiliary reins can be useful: when lunging, for beginners, when correcting a horse that has been ridden incorrectly, or sometimes when jumping or cross-country riding. It is best to ask your riding instructor or trainer for advice on whether and which auxiliary reins you need and what the correct buckling looks like for your horse. As with all aids, it is important to make the right choice and to use auxiliary reins sensibly and correctly.
The martingale, or running martingale, consists of two rings through which the reins are pulled. These rings are attached to a leather neck strap or to your horse's bridle with a leather strap. The martingale is mainly used in jumping and cross-country for horses that throw their heads up a lot. It must be buckled in such a way that the two leather straps are slack when the reins are normally applied. It is only effective if your horse's lifts its head too high.
The martingale should not be used on horses that suffer from headshaking syndrome. With these horses the martingale would have a constant and too strong effect, which they would not understand because the head twitching movements are involuntary.
The side reins consist of two leather straps which are directly connected to the bridle rings from the side of the saddle girth. They simulate the rider's steady rein connection when lunging or for beginner riders. However, they can also appear very rigid, even if they are not set too short. As they hardly allow the horse to stretch, they should only ever be used for a very short time during the working phase. They should never be used in cross-country or when jumping, as your horse will not be able to balance itself with its neck as usual and therefore there is a risk of falling.
Standing martingales, like running martingales, are designed to prevent your horse from holding its head too high. However, they become very rigid if your horse raises its head too high. The standing martingales are leather straps that run from the girth through your horse's front legs to the bit. Unlike the running martingale, the rider cannot vary the effect of this auxiliary rein by adjusting the size of the reins. It always has a direct and rigid effect. This auxiliary rein is therefore not at all suitable for jumping and cross-country riding.
The so-called draw reins consist of two leather straps. These run from the saddle girth through the front legs, are pulled through the snaffle rings into the rider's hand and are held like a second rein. This auxiliary rein, more than any other, belongs only in the hands of professionals. For the sensitive, experienced rider, loop reins can help correct badly ridden horses.
Horses that like to push their neck and back away while being ridden can be shown the way down in this way. It is important here that the auxiliary rein is only used to make the horse understand the stretching posture and never to force it to the hand. Since the effect can be determined by the rider at any time, professionals can also jump with this auxiliary rein. Horses that are naturally tight in the neck should never be ridden with loop reins.
Triangle reins are draw reins that do not end in the rider's hand, but are attached to the side of the girth. This creates a triangle between the attachment at the bottom of the girth, the side of the girth and the horse's snaffle rings. Correctly buckled, it allows your horse to stretch deeply forwards and downwards and is therefore often used for lunging. When your horse lifts his head, his nose comes a little closer to the vertical.
Compared to the side reins, this auxiliary rein is not as rigid and allows both stretching and working phases when riding. However, you should never jump with this auxiliary rein.