Correct leg aids to engage the horse's impulse to get the horse to move forward (like karate chops, same time each leg). pressure from one leg to move the hind quarters (laterally). collection, a little pluck below line of barrel.
This counter-canter exercise will help you to exercise your horse while working the horse’s neck, shoulders, rib cage and hips at the same time. It is also good for teaching a horse balance and collection. by reva