Essentially, the trajectory of the jump is determined by the horizontal speed at take-off, the initial striking of the fore-hand and thrust of the hindquarters; It is therefore largely predictable when the hind feet leave the ground, particularly with regard to its Summit.
However, the horse still have some resources to change the shape of this current trajectory. It is the set of these resources that determines the elasticity of the jump.
They include:
The elasticity characterization is subjective and measured evaluating the implementation of the means mentioned above, in some extremes, situations, linked to a risky take-off point or an unexpected obstacle shape or size.
It will be measured in causing these situations through the change of position of the first fence of the line, or by setting width or height of the main fence after several similar jumps and observing the reaction of the horse.
Elasticity is an obvious quality for very high level sport but also, and especially, for amateur at medium and high level sport, in which risky or imperfect approaches seek regularly implementing the qualities of elasticity. Do not confuse it with the suppleness even if suppleness is important to implement the elasticity. An «elastic» horse is flexible but a flexible horse will not necessarily be "elastic".
This quality is highly important because it is difficult to obtain it through the training and it allows the carefull horses to demonstrate their quality. Its heritability is uncertain, what does not mean that it does not exist, and itself is often common to sibling. It must not provide the horse to produce the necessary effort of propulsion necessary to the proper execution of the jump. Paloubet d’ Hallong is a very good example of extreme elasticity.