When the horse goes with a lowered back.

When a rider get up on a horse, the horse's natural reaction will be to lower the back. When the horse lowers its back, the vertebraes will come closer to each other. If this happens, the horse will not be able to work properly.

The horse will then find it difficult to step under himself. It may be difficult for the horse to bend. The fore and hind end do not work in harmony with each other, that is, the horse is struggling to keep the rhythm. The body's "shock absorbers" are put out of service and the horse's joints are put under heavy load, which can cause lameness, unnecessary wear and kissing spine. It goes without saying that this can not be particularly pleasant for the horse.

What is the most important thing in connection with the training of the horse?

It is to teach the horse to work properly over its back. This means that the horse must learn to work with its back up/lifted.

Amaze steps deep under herself and lifts her back

The strange thing is if you search on the internet, there isn't really much to find on the subject. And often when you finally find a good text about it, the pictures do not fit. At least not in the way I would expect it should look like.

The horse's nature is to go around and seek food. It spends hours wandering around with the mule in the ground and feeding grass if there is enough space and grass to do so. It is slowly moving around with most of its weight on the forehand, but it is not something that is harmful to the horse because most of the time it takes place in walk and it does not carry the weight of a rider.