A gentlehalf-haltcan result in the hind end rounding so the legs step deeper, the back assuming more of a "bridge" that can carry the weight of the rider and the poll and jaw softening in response to the bit contact. The whole outline of the horse looks round, as does the movement....
aids trot to walk voice, maintain position (shoulders back!) drop weight, check and release posting trot (b1p31, b2p25) more comfortable for rider and horse, correct diagonal helps horse balance. allow horse to push you forward - forward m...