Riding aids are the cues a rider gives to a horse to communicate what they want the animal to do. Riding aids are broken into the natural aids and the artificial aids.
It is important to remember that the aids are used in a spectrum, from very light to very powerful, depending on the response desired. A very sensitive horse may readily jump forward from light touch of the leg, while a dull horse may require a kick to get the same response. Additionally, an aid from canter to walk, for example, will use slightly more restraining aid on a particular horse than that horse would need going from canter to trot.
Positioning of the legs, seat, and hands are also used in a spectrum according to the individual horse and the response desired. For example, the aid for the canter depart may require the leg to be in a slightly different place than when it asks the horse to bend, or when it corrects hindquarters that are falling to the outside.
In all cases, good training aims for the horse to be responsive at the slightest cue, rather than requiring harsh aids to get the animal to respond. This is one reason why better-trained animals can be harder to ride, as they will respond to the slightest movement or shift in weight made by the rider. Therefore, they will take any mistake made by the rider as a cue to do something (such as a slight pinching of the legs as a cue to run forward, or a slight imbalance in the rider's seat as the cue to step sideways or speed up). Riders must therefore be sure that any perceived "disobediences" are not actually caused by their own doing.
Good training of the rider will aim to produce someone with an "independent seat", meaning someone who is able to give the aids independent of each other (without, for example, sitting forward while adding leg). The rider's first task is to learn to ride the horse without interfering: keeping a steady contact with the bit, sitting in a balanced, relaxed position that allows them to absorb the horse's movement, and keeping a steady, quiet leg that does not pinch, bounce, or push forward or back. Only then will the rider be able to really start to influence the horse in such a way to help it.
The leg, along with the seat, should be the main aid for the horse. It has a great deal of control over the horse's hindquarters, and is used to cue the horse to go forward, increase impulsion (power), step sideways, and correctly bend. It is the primary "driving aid" (cue to ask the horse to increase forwardness or power).
Both legs in a neutral position (neither forward nor back), applying equal pressure against the horse's sides, generally asks for an increase in speed or an upward transition (such as walk to trot). Depending on the level of restraining aids (seat and hands), the leg can also ask for an increase in impulsion, for collection, or even for the rein back. To ask a horse to back up, a rider simultaneously uses soft rein aids to keep the horse from stepping forward, but uses the legs to ask for movement, so the horse moves backwards. It is incorrect to ask for a rein back by pulling or jerking on the reins.
One leg in a neutral position, or slightly back from neutral, when applied more than the other leg, will ask the horse to step sideways from its pressure. Depending on the amount of restraining aids (seat and hands), this can cue various lateral movements, ranging from a leg-yield or half-pass, to a sidepass, to a turn on the haunches or turn on the forehand, to a pirouette.
One leg further back, in a supporting passive role, and the other leg in a neutral position, but active role, will ask the horse to bend toward the direction of the neutral leg. For example, on a circle going to the right, the rider will put his or her outside leg slightly further back, and use the inside leg at the neutral position to ask the horse to bend correctly through his body. This is also important when cueing for movements that require bend, such as the half-pass, or pirouette.
One leg farther back, with the other leg in a neutral position, both actively encouraging the horse forward, will usually aid the horse to canter. The horse will pick up the lead opposite the leg that is further back.
The hands communicate to the horse through the reins to the bit. They have the most control over the horse's head and shoulders, and relatively little control over the animal's hindquarters. Generally, the legs and, in some cases (such as dressage), the seat should be more prevalent in giving cues to the horse. Many beginners over-use the hands, before they begin to learn the more sophisticated methods of using seat and leg to ask the horse to turn or slow down. The best riders on very well-trained horses can sometimes ride bridle-less, using only their seat and legs to communicate with the horse.
The hands are used for two main purposes: as a "restraining aid" (an aid that blocks or contains the forward energy of the horse) or as a guiding aid, encouraging the horse to go in a certain direction.
Both hands, pulling backwards and used together, act as a restraining aid. Depending on the amount of restraint the rider uses, this may ask the horse to halt, perform a downward transition, reinback, or bring his hind legs further under his body, increasing impulsion or collection. As a restraining aid, the hands should be used in conjunction with the legs. If the rider slows "all in the hands" (without any use of leg) he creates an unbalanced transition, with the horse on the forehand. This balance of leg and hand is something that must be learned by the rider, and most beginners will halt simply by pulling backwards on the reins.
One rein used more than the other can create a guiding effect. There are 3 main turning aids using the hands, in which the inside rein directs the horse in the direction of the turn. However, all should be used with an outside supporting rein, to keep the horse's shoulders straight, and to contain the energy.
Raising the hands causes the pressure of the bit to act more on the horse's lips (as opposed to bars of his mouth). Although this is not the usual position, it can be used occasionally as a training tool.
A harsh jerk upward with one hand (with the other firmly planted on the neck) is used in a technique called the "one-rein stop." This is an emergency technique, when the horse is running away with his rider and no other method will stop him.
Western-style riding employs the use of the neck rein. The rider, holding the reins in one hand, moves that hand one way or the other so that the reins put pressure on the neck of the horse to ask it to turn. The bit does not come into play. This technique is also used occasionally by English-style riders.
Like the leg aids, the severity of the hands can communicate different things. So a slight resistance backed up with the leg can act as a half-halt, where as a larger resistance will communicate to the horse to halt.
Opinions vary on the definition of "the seat", but most agree that it includes the rider's hip region, including the seatbones and the pelvis, the thighs, all of which must be supple and balanced to correctly absorb movement. The seat is one of the more difficult aids to develop, because the rider must first learn to relax and sit the horse without bouncing or interfering, and then learn apply the seat as an aid. The human center of gravity is just above the pelvis. By tilting the pelvis very slightly backward (pulling the stomach in, but remaining a 'long upper body') the point of gravity will shift and the horse will slow down or halt. By pushing the pelvis half an inch forward, the point of gravity will encourage the horse to move "faster".
Most of the time, the seat stays in a neutral position in the saddle, neither restraining nor encouraging forward movement, simply following and absorbing the horse's motion. In general, the rider's hips should be placed so that they mimic the position of the horse's hips, and the rider's shoulders mirroring the position of the horse's shoulders. This allows the rider to follow the movement correctly, helps to keep the rider balanced in the saddle, and helps to guide the horse with minimal effort.
The seat can be used as a restraining aid, by temporarily stopping its following movement with the horse. This is usually used in conjunction with the hands, with some support from the legs.
By weighting one seat bone or the other, one can encourage bend in that direction. This should always be used with the inside leg asking for the horse to bend around it, and the outside leg providing impulsion for the bend. The hands also ask the horse to bend, with a slight direct or indirect rein. A more advanced form of this set of aids is seen in the half-pass, where the outside leg asks the horse to step over, the inside opening rein encourages that movement, and the inside seatbone and leg maintain the bend in the direction of travel.
One seatbone may also actively push forward and sideways into the horse, to encourage the canter depart. This is used in conjunction with the legs and hands in their appropriate places.
Lastly, the seat may be used as a driving aid, if the rider shifts their hips and slightly backwards and pushes both seatbones into the saddle (as one would if pumping a swing). This technique is generally discouraged, as this is considered uncomfortable for the horse, causes a loss of suppleness through the hips for the rider, and the legs should be the primary driving aids.
Horses are very apt at learning verbal commands: "whoa," "walk," "trot," "canter" or similar words are quickly understood. The actual words usually do not matter, as long as they are consistent, though the tone of voice and the accenting of the word have an influence. A calming tone helps accentuate commands to slow down, an upbeat voice may emphasize commands to move forward. A kind voice tone may be helpful when praising a horse, and a harsh or growling tone when reprimanding. However, overuse of the voice (like overuse of any aid) can dull the horse to its effects. In general, it is best to rely on the leg, seat, and hands over the voice when riding.
Riding school horses, who hear instructors telling the pupils what do to, are known to obey spoken commands, which sometimes gives the false impression that the horse is obeying the rider. Likewise, experienced show horses will sometimes respond to the commands for changes of gait given by the announcer over the public address system rather than listening to their riders.
The spur is attached to the rider's boot, and is used to back up the rider's leg aids. Spurs are not designed to be used as punishment. Use of the spur can range from a brief, light touch, to encourage more impulsion, to a sharp jab on a horse that refuses to go forward. The spur should only be used by experienced riders.
Though what degree of force constitutes abusive use of the spur may vary between horsemen, spurs should not be used to the point that they draw blood. Additionally, many equestrian organizations have strict rules regarding the type of spur (generally requiring it to be blunt), and the length allowed. Spurs with rowels (small rotating wheels which sometimes have dulled points) may or may not be allowed, depending on the discipline and organizational rules.
The whip is usually longer and more flexible than a crop or bat, and has a lash at its end. The whip is used to back up the rider's leg aids. Additionally, it may be used as a training tool, using light taps, when teaching the horse to collect their gaits or perform movements such as the piaffe. Types of whips include:
Length of whip is usually regulated by equestrian organizations.
Most equestrian organizations have rules regarding use of the crop. This includes regulations on the maximum length, the maximum number of times the horse may be hit, where it may be hit (most do not allow for the crop to be used anywhere near the animal's face), and circumstances it may be used in (for example, it may be used after a refusal, but not after the rider has left the showing arena to "punish" the horse for putting in a poor performance).