At times, we see the Icelandic Horse ridden in a forced frame, the head and neck pulled up and back. This action hollows the horses back. While the gait of the Icelandic Horse may require a little ventroflexion, this extreme ventroflexion is unnecessary. It also makes life (and being ridden) painful for the Icelandic Horse.
The image below will give you a little insight as to what happens in the neck and head of the horse when they are forced up and back. At rest, the Icelandic Horse has ample room for his neck bones, trachea, tongue, glands, etc. When he is forced to travel with his head and neck up, it pushes the neck bones into an unnatural angle, jams the tongue to the back of the throat, painfully squashes the parotid gland*, and restricts swallowing and breathing.
If you have ever watched some of the video of Icelandic Horses, you may see their heads tipping at odd angles, looking for some relief from what is being done to them.
The neck telescoping gesture raises the base of the neck, and the throat latch becomes more open. This is what we want to happen! It also allows the horse full range of motion in using his head and neck for balance and vision. See Neck Muscles for further information about which muscles in the neck are working in each of these different frames.
*Lymph nodes of the head and neck include the parotid gland. The parotid gland
wraps around the cartilage of the base of the ear.
When ridden, increasing the pressure on the parotid gland, the poor horse
will twist its head trying to relieve the pain, which results in the horse
hollowing that side and the other side of his poll becomes stiff. In other
words, the twisting of the horse's head results from the resistance in the
rider's hands and the corresponding resistance in the horse's jaw. To
correct a slight tilting of the horse's head, take a lighter contact on the
Massaging the parotid gland: Take your fingers and lightly take hold of the
parotid gland. This should elicit a little pain from the horse. As the horse
becomes more supple and flexible in the poll, you should be able take a
firmer hold of the parotid gland and be able to massage it without pain.
After proper gymnastic exercises, you will be able to close your fingers
around the entire gland and massage it from the bottom of the gland to the
top of the gland, at the poll, without pain. The horse should
then no longer be stiff in the poll.