Learn leg aids: when the leg drives, moves sideways or contains, and why short, clear signals work better than constant pressure on your horse.
Why doesn't my horse react to my leg? The honest answer: often it is not the horse but the duration of the pressure. Horses learn through pressure and release: the release is the reward. Equitation science experts stress that the release must be prompt, consistent and easy for the horse to achieve [1]. Constant driving, on the other hand, turns the signal into background noise and can make a horse dull or over-reactive [1].
What can be measured for leg aids is shown by a study with 11 riders: the forces of the riders' legs were much more irregular than the rhythmic pressure in the saddle. In travers the outside leg reached a mean maximum of 47.2 newtons, riding straight 31.6 newtons [2]. That is roughly 3 and 5 kilograms of force, about three to five litres of milk in cartons. How much of it the horse feels, the study does not say.
And one more finding from a survey of 1,819 horses: the more people regularly rode or handled a horse, the harder it was to accelerate. The authors suspect that horses learn rein and weight signals more persistently than leg signals [3]. For you it means: your leg has to stay clear and the same.
Let the lower legs rest on the horse's belly without gripping and without plucking. The FEI asks for a leg "steady and stretched well down" [4]. Milestone: You can ride a lap of walk without your leg slipping or swinging back.
Press both lower legs briefly at the girth and release immediately once the horse steps forward. The horse should learn that stepping forward ends the pressure [1]. If it stays sluggish, repeat briefly and clearly and ask your instructor about technique. Milestone: Your horse steps forward on a light impulse and stays in rhythm on its own.
Act with one lower leg a hand's width behind the girth so that the hindquarters step sideways. This is riding-school practice (leg position). In lateral movements that follow later the connection is measurable: in travers the force in the outside leg rose compared with riding straight [2]. Milestone: Your horse steps one step sideways at the walk without rushing.
The outside leg rests behind the girth and limits the hindquarters so they do not swing out on turns. It is a calm, passive aid, active only when needed. Milestone: The horse stays on the track on a circle and the hindquarters follow the forelegs.
After each right reaction you take the pressure away immediately and praise. A study on backing up from the rein (20 horses) found that horses that first answered with other behaviour needed longer and more rein tension [6]. That is a rein finding that I transfer to the leg: the clearer the signal, the less force.
Leg aids do not replace supervised training. As a beginner drive only at the walk and with an instructor until you can control your horse safely. If your horse reacts to light aids at once with bucking or rearing, do not drive on but dismount and get help. The literature warns that a signal that is not released can push the horse to unwanted, sometimes dangerous reactions such as bucking, because it does not know how to escape the pressure [1]. That is an argument for clear, short aids. And: a horse that constantly answers leg aids with tail swishing or teeth grinding may be tense or in pain [5]; whether pain is the cause is for the vet to clarify.
Ride a lap without a whip, only with voice and impulse: a single click of the tongue and a short leg impulse, then quiet. If your horse steps forward reliably on that, your leg is clear. This is training practice; there is no study evidence for it, but the principle "short signal, immediate release" is well supported [1].
As firmly as necessary and as lightly as possible. Measured leg forces averaged around 32 to 47 newtons [2], but that says nothing about how much your horse needs. What counts is that you release at once when it reacts [1].
Common reasons are constant pressure, changing riders with different signals or too little clarity. A survey of 1,819 horses found that more riders or handlers went with horses that were harder to accelerate [3]. Have your instructor check your leg.
As a beginner no, only after explicit clearance by your instructor. The FEI does not tolerate abuse of natural or artificial aids such as spurs or whips [5].
The outside leg lies behind the girth and limits the hindquarters so they do not escape in turns. It is a calm aid that becomes active only when needed.
They reinforce each other. The FEI describes the half-halt as a coordinated action of seat, legs and hands [4]. The leg gives the impulse, the weight supports the direction.
Rein Aids: Taking, Giving and Flexing With a Soft Hand