Shoulder-in is a useful suppling exercise that requires the horse to work on three — or sometimes four — tracks. In a three-track shoulder-in, the outside hindleg is on one track, the inside hind and outside fore are on a second track (in line with each other, as per the picture above), and the inside fore is on the third track. When viewed from the front, you should be able to see three of the horse’s four legs when it is being ridden correctly.
The horse should be bent around the rider’s inside leg with equal bend through the body and the neck. As a rider you should be able to see your horse’s inside eye if you glance down. It is easier to ride shoulder-in on the track as the fence/wall helps to guide the direction. More experienced partnerships should try riding it on a three-quarter or centre line to gauge their level of control.
In dressage competitions, shoulder-in is ridden in trot, but for training purposes it can be ridden in all three gaits. A more subtle version of shoulder-in, called shoulder-fore, is useful for correcting the horse’s natural instinct to move slightly quarters-in while cantering.
Correct aids for shoulder-in
The rider’s inside leg is on the girth to create the bend and send the horse along the required track. The outside leg is slightly behind the girth to prevent the hindlegs swinging out and maintain bend through the body. The inside hand asks the horse to flex to the inside and keep the jaw soft. The outside hand asks the horse to wait and indicates that the horse is to continue down the track, rather than turning on to a circle. The rider’s body should remain central in the saddle with the inside hip slightly back to mirror the horse’s bend and the weight deeper into the inside seat bone.
Common problems and how to correct them
Problem: Your horse drifts back to the track
Correction: If your horse drifts back to the track, you may be looking in the wrong direction. Check you are looking through the horse’s ears rather than in the direction of travel as your head is a heavy body part, and will affect his balance.
Problem: Too much neck bend
Correction: If your horse bends his neck more than his body, check you aren’t using too much inside rein. Support him with a firmer contact on your outside rein and by keeping both legs on.
Problem: Hindquarters drift out
Correction: If your horse’s haunches drift out to the outside, your knee and thigh and lower leg are not supporting him strongly enough, resulting in lack of bend through his body. Check your outside leg is correctly positioned behind the girth and against the horse’s side.
Problem: Falling through the shoulder
Correction: The rider crossing the outside hand over the neck is a common cause of the horse falling out through the outside shoulder. A correct contact on the outside rein supports the horse’s shoulders and helps to maintain the angle of the shoulder-in.
Problem: Your horse doesn’t step sideways, but continues going in the direction of the bend.
Correction: This can stem from a lack of preparation from the rider or a lack of understanding from the horse. Use half-halts to maintain the self-carriage of the horse through the exercise and ensure he is listening. If the horse is green, return to leg-yield exercises to re-establish the horse’s understanding of moving away the inside leg before trying shoulder-in again.
Problem: Lacking bend through the body
Correction: Sitting on the wrong seat bone, and collapsing through your waist to the inside may cause your horse to lack bend. Try to deepen the inside seatbone, while remaining tall through your upper body.