Jennie wrote to ask about fixing her horse's high head set: "Hi, I wonder if you have any experience or ideas for a horse who has a high head. It's like he is stretching out to see over the top of something, not really at the walk but at the trot. Other riders have given me various advice such as to use a tiedown or a head setting device that goes over their neck? My research has also made me consider a martingale. I have also seen competition where a horse is ridden and his head is down close to the ground. Is this called collection? What is the advantage of teaching a horse to ride like that? Any ideas or food for thought would be appreciated."
The competition you are likely talking about is reining and those horse's are being ridden with true collection - nose vertical to the ground, the poll is flexed, and the horse's back legs up underneath their body's, the stride is short and quick, rounding the horse's back. Basically this lightens up the front end where normally greater than 50% of the horse's weight is carried and transfers weight to the rear end in order to work on the back end which helps for better stops, transitions, lead changes and more.
Along with the reining you saw, you will also dressage horses ridden displaying vertical flexion. Sometimes you will see horses ridden with exaggerated flexion where their nose is very close to their chest. But just because a horse is flexing at the poll doesn't mean it is collected. In the picture above left I am riding at a walk and am asking my horse to soften his face, flex at the poll.
All this begins with the horse giving to pressure during ground training then progressing to vertical flexion in the saddle, then flexing at the poll during the walk from very short moments to longer times as he gets soft. Then begin again at a trot and so forth. You get collection when the horse's flexes at the poll and you drive the horse's back end up underneath him rounding the back.
For most people to enjoy their horses, pleasure and trail riding and even local competitions, it is likely not necessary to ride your horse with collection. However, getting your horse to soften and giving to vertical flexion has got to make a better horse and partner.
With your horse's high head set his back is hollowed out and the majority of his weight is on the front end. The center of his eyes are higher looking more further and forward. He can still see the ground and obstacles to his front as he travels as horses have great peripheral vision, but not as good as if he had a more horizontal head set.
In the photo at right, I am riding at a jog and my horse has a natural head set. There is a reason it is called a natural head set - it is simply natural for the horse. Watch a horse in a pen when something attracts his attention. His head goes up to the necessary height where he can look out of the center of his eyes to determine the threat.
So while you may likely need to work on getting your horse soft and giving in the face, working on vertical flexion, there is nothing wrong, and everything right about riding with a natural headset. But I'll give you my opinion on the rest of your question, concerning tie downs and other devices.
I'll assume you have eliminated your horse's teeth, the bit and how the bit is seated as a source for your horse's high head. But I am not a fan of, nor a user of tie downs or the head setter which is likely the "head setter device" that you were advised to try. A tie down is basically a type of cavason around the horse's nose and tied off to the breast collar, or through the breast collar ring to the cincha. The tie down limits how high the horse can raise his head. It is typically used in arena roping and thought to give the horse something to brace against upon the jerk of a steer on a rope. Virtually every team roper using one. I will defer to their experience as to the necessity of a tie down for roping.
The head setter is a combination nose band and rope over the poll which if the horse raises it's head or nose pressure is applied to the nose and/or poll. Some of the head setter devices are rope and some are even plastic coated cable. Effectiveness is dependent upon the horse bringing his head and/or nose back down to release or escape the pressure.
Mikmar makes a bit with a rope tied from one shank of the bit, up over the nose of the horse then connects to the other shank. When the shank are activated, pulling on the reins, the rope over the nose tightens and the theory is that it provide a signal that is spread out fro the bit, to the curb and nose band tightening to the headstall applying poll pressure to the horse to drop his nose and lower his head to get relief. I have no experience using Mikmar bits, but their are obviously some riders who believe in them.
As far as Martingales, there are two basic types - a German Martingale and Running Martingale. I have never used a German martingale, but have used a running martingale which is a strap connected to the breast collar, or through the breast collar to the cincha, and has two legs, each with a ring for the respective rein to pass through then connect to the bit. See my diagram below and no wise cracks on my artistry please. There is usually a rope or a loop that goes over the horse's head and sometimes a strap that connects to the gullet of the saddle prevents the neck rope from running up towards the ears.
The running martingale is adjusted so that it provides a fulcrum (through the rings) when the horse head is at a certain height encouraging the horse to drop his nose. I made a German Martingale for a client and was asked to do a couple extras, but then I changed my mind about offering them to people as I think there was potential for people to get into trouble using them as a short cut to getting their horse soft.
So what I might do with you horse who has a higher natural headset, is to work on getting your horse soft and giving in lowering his head. Again, first on the ground, then in the saddle, then at a walk all before you ask for vertical flexion at the trot. There may not be anything wrong with riding a hors with a natural headset, but getting your horse soft and giving can only help both of you.
Now that I have used up my annual allocation of words, see if this helps you and let me know ho you and your hose are doing. Safe Journey, Jennie.