Learn rein aids safely: soft contact, taking and giving in tandem with seat and leg, and why a quiet, following hand protects your horse's mouth.
How hard may I pull on the rein? The honest answer: not at all. Good rein aids are short signals that release at once. The FEI describes the aim for the hand as "steady, close together, a straight line from supple elbow through the hand to the horse's mouth", and the contact should be independent from the seat [1].
Why this is more than riding romance shows in measurements: rein tension fluctuates with every walk step and every trot stride. At walk it was highest when the hind limb was on the ground, at trot it was highest in the suspension phase [2]. If you sit with a rigid hand you turn that into jolts. Tension also varied strongly between riders and horses [2].
And the measured values are not harmless: a review compared rein and bit pressures reported in studies with human pressure pain thresholds. The lowest reported values (about 91 to 108 kPa) would lie below the threshold of the human hand (445 kPa), the highest (about 1,314 to 4,286 kPa) many times above it [3]. That is a comparison, not proof of how a horse feels, but it advises caution.
Carry your hands upright, thumbs on top, forearm in a straight line to the mouth, elbows close to the body [1]. In measurements the hand stays astonishingly quiet: through coordinated movements of shoulder and elbow the wrist stays within about 15 millimetres of the bit per stride, the width of one finger [4]. Milestone: Your hand looks quiet although your body moves along.
Contact is a light, even connection to the mouth, not a tug of war. It must be soft: the FEI names "resistance to or evasion of the Athlete's hand" as a sign of lack of submission [1]. Milestone: The horse chews contentedly and the head stays calm.
Briefly close your fingers ("take") and give in the same moment as soon as the horse reacts. The giving is the reward. In a study on backing up, horses showed more evasive behaviour with head, neck and mouth as rein tension and the duration of the signal increased [5]. Milestone: After each take the horse's head settles.
With the inside rein you flex the horse slightly toward the bend. The outside hand limits and holds the shoulder. Do not pull back on the inside rein; carry the hand lightly inward. Milestone: From the saddle you see only the inside edge of the eye.
The hand is the third aid, not the first. The tension just before a transition was the strongest predictor of the tension in the transition [6]. So ride softly before the transition. Milestone: Your horse changes tempo without the rein getting tighter.
Rein aids do not replace supervised training. As a beginner you always practise them with an instructor and at the walk. If your horse throws its head up, opens its mouth, tosses its head or blocks, that does not mean "disobedience". Experts point out that terms like "resistance" or "evasion" can hide pain and overlook the horse's motives [7]. The behaviour is a hint, not proof: bring in your instructor and, if needed, have bit, teeth and back checked. Never tie or hook the reins to the horse to fix its head.
Ride a lap at the walk with contact like holding a bird: firm enough that it does not fly away, loose enough that you do not crush it. If your horse chews softly and the head stays calm, the dose is right. The image is riding-school practice; the measurements only show how strongly tension can fluctuate [2].
There is no universal figure. Measurements show large differences between riders and horses [2]. What matters: the hand follows the head movement and gives at once when the horse reacts.
It may be restlessness, tension, an ill-fitting bit or pain. Experts advise not to read such reactions as disobedience but to clarify the causes [7]. Ask your instructor and, if needed, a vet.
Yes, in competition riding with both hands is obligatory; one hand is allowed only at the salute and after the test [1]. In training both hands are the basis so that both reins stay equally soft.
Taking is short and releases at once; pulling lasts. If your horse reacts with evasive behaviour, it was too long or too strong [5].
The FEI requires a snaffle bit as the main contact in dressage [1]. For beginners what counts is that the bit fits and the hand stays soft; whether bitless riding is better is not the topic here and not part of these sources.
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