Impulsion allows any horse gait to be more elastic and light, and also provides the animal with the power needed to perform complex movements, including the piaffe and the airs above the ground. Within the dressage world, there is an unresolved debate whether impulsion can only occur in gaits which have a period of suspension, the trot and canter, or if it occurs at any gait, including the walk and the ambling gaits.
The concept of propulsion enables horses to perform more elastic and light movements, including the piaffe and airs above the ground. In the dressage world, there is an ongoing debate about whether this ability is exclusive to gaits with a moment of suspension or if it can occur in other gaits as well.