There is too much bend in the neck
How to put it right Generally, this is caused by the rider trying to pull the horse's forehand to the inside with the inside rein. This bends the horse's neck too much and pushes him through the outside shoulder therefore blocking the horse from moving forwar<± Control the bend with the outside rein and guard the hindquarters with your outside leg, to prevent them from swinging into the fence.
You collapse through the inside hip
How to put it right Make a conscious effort to sit centrally in the saddle with your weight evenly distributed over both seat bones. Too much emphasis can be placed on putting more weight onto the inside seat bone, but this ^ often causes riders to collapse through the inside hip. This in turn makes it more difficult for the horse to perform shoulder-in. Think about growing tall from the waist and being long in the leg - in other words, elongate up and down from the waist.
The horse drifts away from the track
How to put it right This can also happen when the rider collapses the hip and pulls to° much on the inside rein. Sit evenly over the saddle, keeping a steady contact on the outside rein. Press with the inside leg and half-halt with the outside rein every other step, to give your horse his instructions for continuing the shoulder-in. And remember - do not pu11 back on the inside rein!
The angle of the shoulder-in is too big
How to put it right This is one of the main problems that riders come across. When riding shoulder-in without the benefit of arena mirrors and looking down on your horse from above, you might feel as if you don't have enough angle. Chances are, therefore, that you'11 over-compensate and make the angle too big, so control the position with your inside leg and outside rein. Looking down is not necessarily a bad thing - in fact, I encouraged Philippa to look down at the angle of the shoulder in relation to the fence (see main photo, left).