All those that wish to work with a creature of another species must have, at the very least, some basic knowledge of the relationship between the anatomy, physiology and subsequent movement generated therein of said species.

If you wish to ride and work with an equine you must know how that beast motors from one spot to the next as well as how quickly this graceful and generous hearted mass of heart and muscle can decelerate before overloading the legs. If humans push harder than the horse can give one or both will suffer acute and/or chronic injury as well as mental stress that can, with a little forethought and knowledge, be avoided.

The subject of equine anatomy and physiology is a multi-semester course of study for Veterinary students so we will only touch upon the subject in this and other articles to follow. I will equate some basic biomechanics to the aids we use to communicate to our mounts and thereby give you a better understanding of why some aids work and why others should be discarded.

We will start with lateral bending.

Lateral flexion or bending does not come from the spine. For the purpose of our understanding as riders let us say that lateral bend occurs in the horse by displacing the rib cage towards the outside of the bend. The rib cage hangs and swings – it does not bend. Displacement of the ribs allows the inside hind to come further under the horse’s center. This then allows the shoulders the needed space to follow the forelegs over. We must ask for a bend keeping these things in mind or resistances are bound to happen. When these resistances occur innovative humans come up with all sorts of tricks and approaches to correct them – usually to no effect other than to add more frustration to the bending attempts and perhaps create sore muscles both equine and human.

To create a lateral bend if you can picture the rib cage hanging from the spine and then feel how it sways back and forth as the horse walks you have the beginnings of how to better ask for a bend. If you push, just behind the girth, as the belly swings away from you this is the correct aid for bending. Of course it is only the beginning. The rider’s inside leg swings the ribs further over and that allows the horse’s inside hind to step further under. As soon as the rib cage has moved over the rider must relax the inside leg aid or the horse will not know that her response was correct. At his point you must limit and direct the bend from the outside by closing your outside thigh – no need to push. This directs the shoulders toward the inside and thusly the horse is bent.

A squeeze on the outside rein may or may not be needed to finish but only if the horse bulges the outside shoulder away from the intended bend but if used it should be a quick squeeze of the fist with no retraction backwards from the arm. This is best done when the shoulder is back indicating that the front foot on the same side is about to leave the ground. This is the only time we can influence a horse’s leg – just before it leaves the ground. The rider’s seat and trunk turn in the direction of the bend, which will put the body in the right position to receive the bend from the horse.

The inside rein does not create a bend and, in fact, does more to distort the bend than it does to assist. The inside rein does nothing but soften the inner jaw if the horse requires such. Resistances such as clamping the jaw shut, locking his teeth on the bit, leaning his neck too much into the bend or away from the direction of the bend can be corrected with a slight sponging or pulse type action of the fingers only and again must not include retraction of the arm backwards. If your bend is executed correctly the inside rein will become slightly slack – hooray – and please do not take back the contact at this point.

If you try to bend the horse by pulling the head and neck with the inner rein you will succeed in throwing the horse through the outside aids - the horse will throw his weight into the outside shoulder and pull himself and you into that direction. I'm sure you have seen this – head and neck pulled all the way over to the left and the horse still traveling to the right - sometimes at great speed. This approach should be discarded.

As the horse complies with the bend the rider must have a clear idea of the next step. Are you bending through a corner, circle, shoulder-in? Based upon your intention of where to go next your body position will indicate to the horse what to do with the bend – follow it or maintain a lateral position along the wall.

There is an old saying that you must ride the horse between your legs. I have no idea who said it but he/she was a genius. If you consider your legs before your hands and how the horse physically functions your riding becomes more ethical, more correct from the horse’s viewpoint and, as a bonus, more successful from the riders’ as well.