This is done by pulling your reins sharply to either the left or right, and make your horse touch its nose to your leg. A horse cannot buck when it is in this position; it can only move in an incredibly tight circle. It also reinforces you as being the herd leader and loosens the horse's muscles up so that it is easier for the horse to move. Do not release the horse until it completely stops moving, and then hold for three seconds. Repeat on the other side, just to reinforce your point to the horse. Every time the horse is about to buck, or starts bucking, repeat. If a horse is prone to bucking, do this every time you get on the horse – both standing beside the horse and once you mount. " Using one hand, gather your reins, and slide your other hand down the reins, creating a tight "scrunch" on the horse's neck.  This triggers a certain vertebrate in their necking, causing them to be unable to buck. Also remember to use your legs, and the horse should back up.  Once the horse has started to calm down, release the pressure of both your legs and reins. A horse cannot buck without putting its head down.  Keep a tight rein so you can pull back when you feel the horse trying to lower its head, thus preventing the horse from being able to buck. Keep your heels down and your shoulders back, and give strong pulls on the reins to discourage the horse from putting his head down. Remember – a horse with their head up cannot buck. Also, make sure to keep your leg on. Many times a rider will try to correct bucking by stopping the horse. It is much more correct to reinforce forward motion. Do not let the horse stop. Many times, horses will learn that bucking can get them out of work. The first thing to do is to lean back; this will highly lessen the chances of you falling forward onto your head. However, if you are not a strong rider, you may find it easier to simply get off your horse. This may sound like a bad idea, but think about it: if you really think you are unable to stay on your horse, would you rather get off it...

How would you rephrase that briefly using Vietnamese?
Khi con ngựa định lồng lên, ngay lập tức làm mất điểm tựa chân sau của nó. Tạo ra một “vòng kẹp”. Nếu con ngựa của bạn lồng lên, hãy ngồi lùi về phía sau yên ngựa. Nếu bạn cảm thấy không ổn, hãy nhảy xuống ngựa, nhưng đừng chạy đi chỗ khác. Nếu bạn đã quen với con ngựa từ lâu, hãy để nó ngửi bạn.