Complex sentence: It is often taught to horses of the Andalusian and Lusitano breeds and is considered a part of the horse culture in Spain, said to benefit the horse by helping it learn to open up its shoulder movement.
Split into simpler sentences: It is often taught to horses of the Andalusian and Lusitano breeds and is considered a part of the horse culture in Spain. The action is said to benefit the horse by helping it learn to open up its shoulder movement.