On the aids, on the contact, on the bit...

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The Complex Contact of the Independent Spiral Seat
On the Contact and Saddling
On the Contact and Injury from Riding Very Deep Behind the Vertical

On the Contact, On the Aids or "On the Bit?"

The distinction between on the contact and on the bit (preferred term "on the aids") is technically the upward adjustment in posture of the spine (red) that the horse makes in response to the aids, especially those of the rider's lower body. This happens when the contact between rider and horse is continuous through both their bodies. "On the aids" produces a unification through what some authors term the "circle of aids." "On the bit" is a term in common use, but it is a preference of this site to use "on the aids" or "on the contact".

Because the horse must rebalance with its center of mass (plus rider!) held higher to be on the contact, its posture requires more muscular effort and thus more energy. Patience is required to allow the horse the time to develop muscle tissue and coordination for each degree of collection on the aids. Remember, the horse weighs half a ton or more plus the rider! And the rider to be maximally effective should be relaxed into moving in unity with the horse.

The "circle of aids" connects a rider's anatomy with that of the horse.
Shaped more like the loop symbol for "infinity," it embraces the wide variety of half halts that can be given to inform the horse of the needs of an exercise.
	<------ LEFT The default setting for the circle of aids in a reasonably advanced horse. The dotted and solid lines give an indication of the intensity of the contact. The rider's seat is particularly responsible for sending the horse "toward the bridle" with a receiving hand. The actions shared by horse and rider are dynamic and continuous.

The dotted and solid lines give an indication of the intensity of the contact while the red section indicates active half halts given as rhythmic touches of the spiral seat, indicating the tempo for the exercise (20 meter circle right). The rider's seat is particularly responsible for sending the horse "toward the bridle" while the rein and arm receive the actions of the seat and legs. (Video camera angle produces a slight distortion of stride length.)	Young horse (Smoke) on the contact showing obedience to aids of seat and leg. His left hind is on the ground in advance of his right fore (positive disassociation of diagonal pair) and he is reaching for the rein. His LH lands in the print of his LF, indicating he is "tracking up."

The request to rebalance the center of mass is called a half halt. Half halts are generally given with the seat and legs with minimum participation of the rein. Half halts are particularly effective when the contact of aids is elastic, supporting and unobtrusive.

It is the function of the rein to provide an elastic connection with which the horse can work. As the horse learns to perform in the "circle of aids," the rein becomes more and more given to sensitive communication with the tongue. For green horses, the rein may also function by touch on the neck surface as a guide for the muscle(s) the horse should develop toward self-carriage. The more coordinated the rein aids, the more the horse can be adjusted with half halts. Work in the high school, with collection in the second degree (and beyond, for some horses) the rein can subtly reinforce the aids from the lower body.

Some horses are so sensitive about seat and leg aids other than their position and intensity of touch that tiny indications from fingers eventually become preferred communication for the tempo of passage and piaffe. At this level of achievement, it is up to the rider to listen to the horse for advice among a number of functional options. What is certainly not desirable is to see the rider busier than the horse!

Click on the images to read the text at full size. Text from the illustrations is also repeated on the page. Colored text blocks indicate discussions of color coded anatomy. The hyoid radiograph is at a link at the bottom of the page.

Axial skeleton (skull and spine (red)

Legs and pelvis (orange)

Rib cage (yellow)

Scalene joins neck to rib cage and centeral abdominal muscles (abdominus rectus shown here) link rib cage to pelvis, completing the "elastic ring" that the rider unifies with the "circle of aids". (lavender)

Comparison of the horse's posture for "on the contact" and "on the bit/aids." RIGHT: Diagrams of the horse's adjustment from the base of the neck toward the head. The "frame" is shorter without constricting the horse's breathing.

BELOW: a horse comfortably on the aids in a halt (Raynyday Maximillian) for collection of the first degree.

To some extent, a horse's conformation affects how he looks on the bit/aids/contact. In the photo BELOW, Max (Morgan) has two pronounced and equal curves in his neck, as do many Friesians and Lipizzaners. Such horses appear to have "a higher set on neck." But a look at the skeletons in the diagrams on these pages should convince you that a horse's spine does not follow the top of the neck (crest).

What varies to give the impression of neck conformation is the relative size and depth of the two curves in the cervical vertebral part of the neck. Two equal but relatively shallow curves are often found in quarter horses. If the lower curve is deep and larger than the upper curve, the horse is "swan necked" or "bull necked" and will be difficult to train for dressage.

Swan or bull necks should not be equated with horses that have become overdeveloped in the lower neck by resisting the aids. Correcting overdeveloped necks is accomplished by expert riding from the lower body without a driving seat. Some trainers have said that it takes at least twice as long to undo a mistake as it did to create the problem...

On the Aids: stretched into rein

The hyoid apparatus is a crucial part of the anatomy for responding to aids from the seat and leg. As a link in the "circle of aids," it allows fine adjustments to be made in relaxed responses from tongue and jaw.

When horses are "through" and "on the bit/aids," tension in the muscles connected to the tongue via the base of the hyoid is relieved by soft munching. This aids the readjustment of the neck vertebrae (reversal of the lower curve from convex toward the ground to concave) for the characteristic "arched neck" in B above.

The hyoid is connected to the styloid process at the bottom of the brain case by ligaments. It connects the muscles and ligaments of the tongue, pharyngeal section of the windpipe and neck. For placing the horse on the aids, this complex set of connections is a major reason to avoid riding with the poll too low or with the neck too short. In the case of "showing a horse the way to the ground" or the exercise of "chewing the rein," the horse is allowed to stretch into the rein while remaining on the contact from a soft, steady lower leg.

Faults with the tougue are traceable to the intimate linkages in the hyoid system. This site takes the position that a horse should have sufficient room in its bridle settings to keep its jaw mobile in order to relieve stresses normally encountered when moving in collection or extension. When making adjustments with tongue and jaw, horses may flick their tongues very briefly out the front of the mouth. If a horse sticks its tongue out of the side of its mouth, over the bit or withdraws its tongue from the bit, it is a sign that bitting, saddling, pressure from the seat combined with a pulling hand or perhaps an injury somewhere in the axial skeleton is a problem.

Clicking on the diagram at right will bring it up larger. Clicking on this link will bring up a veterinary radiograph with web citation.

NOTE THAT THE VETERINARY COMMENTS INDICATE HOW ATHLETIC PERFORMANCE COULD BE AFFECTED BY HEAD POSITION. OVER-CONTRACTION OF THE NECK (TIGHT IN THE NECK) MIIGHT COMPROMISE FREEDOM OF BREATHING IN THE AIRWAY THAT PASSES THROUGH THE HYOID APPARATUS.


This young Morgan (4 1/2 years for driving, 5 years for riding) shows understanding of the contact. He reaches for it with a head position that allows unrestricted breathing. "On the contact" position of this sort can help reduce stress from requiring a nearly vertical face position that affects the shape, diameter and physical properties of the airway. His trot in at least level balance with the hind foot of the diagonal pair landing slightly before the forefoot (very slight positive disassociation of diagonals). His walk is active and forward with light rein connection whether or not he is being ridden (below) or driven (lower right).