Horse and Rider Dynamic Posture & Evaluation With Saddle Explanation. 

The science of posture is relatively new and as such lacks consensus as to how it is defined. Posture is a component of movement, much like nutrition and communication but posture is the movement control component. The communication component is important for horses as they are highly reliant on posture for gesticulation. Pain alters posture to the extent that horses in pain or discomfort, particularly in the back, can be considered non-communicative.