The spine is a key element in a horse’s anatomy and conformation. Stretching from the poll to the end of the doc, it “…allows a range of movement such as lowering and raising the head, arching or dipping the back and bending from side to side” . The back, consisting of the thoracic and lumbar region is an important part of the spine as it assists in forward propulsion.
“The horse is rear wheel drive, the power created by the hind limbs is transmitted along the back in a forward thrust” . The horse’s hindquarters are very powerful and are the prime source of propulsion. The sacro-iliac joint between the hindquarters and the back allows the horse’s hind legs to swing forward and underneath the horse, creating a more powerful stride. The horse’s back rounds and hollows in order to allow this movement.
The back is also important as it is “a bridge between the horse’s forehand and his hindquarters” . The spinous process of the back is covered by the supraspinous ligament, which continues into the neck as the nuchal ligament. When a horse stretches their neck forward, the nuchal ligament is “put in traction” , and causes the horse’s back to lift.
One of the reasons the back is so important for riders is simply because we sit a saddle and ourselves upon it. However, “Putting a saddle on a horse is bound to interfere with the movement of the back to a greater or lesser degree” . Understanding the importance of the back for propulsion and its connection to the forehand, helps us to understand the necessity of protecting such a key element in a horse’s anatomy and conformation.
 Firth, J 2010, Looking After your Horses Back, Amazon
 Dr. Heuschmann, G, Functional Anatomy of the Horse – Back, trans. R Abelshauser, Dressage Today