http://standardbredhorses.yuku.com/topic/459
Whether a neck is long, or short, it still has the same number of bones and joints (7 bones 8 joints). What makes a long neck long, is those individual bones are longer than in a short neck.
Think of these 2 images - a pearl necklace with 50 pearls, and a freight train with 50 cars. Just because a neck is short, doesn't mean it can't bend. The ability to bend in the neck (either arch it, or side to side) is determined at the joints, not the bones - same as a necklace or a train. A short neck has more joints per foot of neck than a long neck. The pearl necklace has more "joints" per foot than the freight train. Which image (or neck) do you think has more potential for bend?
The shape of the neck bones inside the neck when viewed from the right side of the horse are "S" shaped. (on the left side it's a reverse "S"). It's not easy to "see" inside the horse's neck because of the muscle development, ligaments etc in the crest of the neck. The neck bones are assembled from 3 different "parts", the upper curve (top of the "S") the lower curve (bottom of the "S") and the middle segment. Each of these segments can be a different size and curvature - nobody writes the letter "S" the same way, and horses vary on what their "S" looks like.
Here are some of the shapes that we have names for:
Arched Neck
When the upper segment is long and middle is medium, and the lower segment is short, the horse is said to have an "arched neck".
Ewe Neck
The exact opposite of the Arched Neck is when the lower part of the "S" on a horse's neck, is the most prominent (longest, largest, heaviest) part of the neck, with a medium middle segment, and a short upper segment, the horse is said to be "ewe necked" or have an "upside down neck". That short upper segment is key in determining the ewe neck and often results in the conformational trait that often goes along with a ewe neck, a hammer head. In the ewe neck, the longest segment of the neck is in the exact opposite location (the bottom) from the arched neck (the top)
The middle sections of the Ewe and Arched neck are the same. It's just either end that they are reversed.
Straight/Flat Neck
Horses who stand with their necks straight out in front, as an extension of their topline, have an upper and middle segment that are both the same size (long) and a small lower segment.
False Ewe Neck
Similar to the exterior "look" of the Ewe neck, BUT the upper curve is medium, the middle curve is medium or longer, and the lower curve is longest. If the upper and middle curves on a horse's neck have some length, this will override (balance out) the ewe neck trait of a heavy bottom. In other words, there is no "short" segment of the false ewe neck as there is in a "true" ewe neck. These horses are not hammer headed.
The most important part of the neck in training is the lower part of the neck as that is where the "rounding" or neck telescoping motion comes from.
So I'm not going to post any samples, but if anybody wants to put pictures up and see if they can identify which of the necks above fit these descriptions, that would be a lot of fun.
I would say that this horse falls into the category of true ewe neck.
Remember the key to determining the ewe neck is the short upper segment. This horse has a short upper segment, medium middle segment and long lower segment.
In a false ewe neck there is no short segment, there are only medium and long segments.
To answer the second question, "hammer head" is how the head attaches to the neck. A hammer head is not genetic per se, except for the fact that having a short upper segment of the neck is genetic, as is any skeletal structure that is not damaged by injury or non-genetic disease.
The key to the hammer head is that short upper segment of the neck. When the upper segment is short, it cannot arch or bend, it's well..... just too short.
When it can't bend, it's straight, (like the handle of a hammer). The horse's head has no choice but to fit on the neck the same way the head of a hammer fits on the hammer handle.
Yes, you have been misled by individuals who see under-neck muscling and immediately draw the conclusion that the horse has a ewe neck. However, muscles are not what conformational assessment is about. Muscles are what "conditioning assessment" is about. Bones are what conformational assessment is about.
So your conclusion is correct. The under muscling of the neck is about how the horse carries himself. Yes, a ewe neck horse moves in a certain way that will cause more muscling on the underside, but so can any other shaped horse.
The top part of your line shoulder start near the base of the ear. The lower cervical curve line should be lower at it's lowest point. The neck becomes the spine - and the spine feeds between the shoulder blades. The last part of your line is following the top of the vertical bones that make up the withers.
