The main aim is to find out how the regulation of spastic muscle tone works physiologically through the use of equine-assisted therapy, also known as equine therapy, in encephalopathic patients. Basic concepts about chronic non-progressive encephalopathy of childhood, also known as cerebral palsy, therapy and the horse are reviewed, bearing in mind that equine therapy is a therapy carried out with the horse, on the horse and taking advantage of the environment in which the horse lives.