On The Vertical

One feature that attracted me to classical dressage is the science behind it. Personally I do not have a strong commitment to a given theory and I am open to new ideas and try to continuously question my beliefs. This approach is a great way to continue learning, but faced with conclusive scientific research I find myself committed to the evidence. One area where I've found myself drawing a hard line is "on the vertical".

Vets have known for decades that when the horse's face approaches the vertical the horses' ability to breath decreases. Cook, in 1981, was the first to comment on the relationship of the vertical to a decrease in the ability to breathe. In 1995 Petsche and Derksen conducted research on head position and breathing obstruction. The findings of the study conclude that as the horse approaches the vertical the horse's ability to breathe will decrease proportionally. The study reports that a horse on the vertical will have 50% impairment in breathing. Derksen later comments on going behind the vertical and rollkur, "An increase would make a big difference. So, for example, if you double the bend you would more than double the resistance. (Horses For Life)" A later study by the University of Bristol confirms Petsche and Derksen's research, "The findings of this study demonstrate that dynamic obstruction of the URT is a common cause of poor performance in sport horses and is frequently complex in nature. Excessive poll flexion is an important contributing factor.”

These studies have found that the angle of the poll changes the shape of the trachea. The trachea becomes long and narrow as the poll angle increases and impedes the horses ability to breathe. The studies found that the horses can breathe out, but not in.


At A (138 degree poll angle), the position of the head held during running, the horse has the least obstruction to the airway. As the poll angle increase from A through to C the horse's ability to breathe will be reduced. At D the horse's ability to breathe will have been reduced by 50% . At E the horse's ability to breathe will have been reduced exponentially past 50%. In other words, the behind the vertical position seriously obstructs the horses ability to breathe.


The heavy horse can tell us a great deal about the effects of the poll angle on the horse. The heavy horse, like other horses, are a completely hind driven breed as their impulsion motor is located in the rear of the horse. When a heavy horse pulls a light load such as a plough or a cart the horse naturally goes into collection. The driver exerts no force on the bit but simply takes up the slack in the reins. In exerting force to pull a plough the horse will begin by pushing off with more force in the hind legs and stepping under so that leg lands at the centre of the horse's body. The increase rear force will cause the rear joins to flex and the hip to lower. The spine will then rise at point were the withers connect to the neck. The lifting of the withers causes the neck to hang relaxed in an arch and the horse's head will hover around the vertical.

Since the horse is allowed to work in any position that it chooses, this tells us that a head position that hovers around the vertical, but does not go behind it, is a position that the horse is conformable with. As long as the horse is allowed to choose the position itself and the nose is allowed to move back and forth from the vertical to ahead of the vertical the horse is happy with the position and is comfortable working in this position.


The classical head position is the same as the one chosen by the heavy horse . If you watch the Spanish riding school or dressage from decades ago, such as the dressage demonstrated by Klimke, you will see the horse's head bobbing in front of the vertical, but never behind it and never held in position.

In summary, these studies have shown that behind the vertical will cause serious breathing problems for your horse. Although it's been the fashion in show dressage for at least three decades to ride the horse behind the vertical or with the head held in place, these teachings will cause harm to your horse. The horse is comfortable with the classical view the vertical and will be comfortable with working in this position.