(15) ...effect of the retaining hand...
...If the rider's hand holds back the horse, weight distributes to the hindquarters and robs the hind legs of their proper oxygenation, thus suffocating self-propulsion (...Schwung...) and the hindquarter's elastic recoil (...Abfedern...). The result is a false locomotion, in which front legs display a jerking catapulting action, whereas hind legs follow in a dull stride...
(16) ...without any hard and/or violent action
...in all school gaits, and particularly in the development of the school trot (which is the basis of the upper school), the rider must adjust and properly fine-tune propulsive and retaining aids. He most certainly must stay away from any harsh and or damaging inputs of his hands... It is his only chance to keep the impulses flowing in the horse's body (...Durchlässigkeit...). They make for those lively, fluent, elevated and rhythmic strides, which at all cost must mark the proper school trot.
(17) ...when is the horse prepared for lessons of the upper school, i.e. passage, piaffe and airs...
...by the time the school trot has developed to a degree of perfection here described, side-passes may gradually increase in angle and collection and will thus further improve the horse's posture. And soon enough the rider, without fear of set-backs in the horse's health or progress, will be able to turn to the actual lessons of the upper school...