On-the-bit:  this is a technical term used and misused in virtually every 
riding discipline.  It is a skill that represents a "work in progress" 
from the simple "put in a frame" to the highest form of collection and 
engagement in High School movements.  To be truly on the bit requires a 
soft and flexible jaw/poll and considerable engagement in the 
hindquarters.  You can only achieve it after years of careful, 
progressive work and it requires a set of muscles developed over time.  
You NEVER go down the trail "on-the-bit"...it is simply ludicrous to 
imagine anything other than a highly trained dressage athlete fulfulling 
the technical definitions for this particular skill.
Instead...let's think about putting the horse "in a frame" with the 
ultimate goal of achieving an efficient "way of going" that approaches 
"self carriage".  Note that all these terms are related but define 
different skill levels while sharing a variety of techniques to achieve 
a given skill level.
For today, let's focus just on the following--
"In a frame":  Where to start?  Should we talk about the green horse?  
Should we talk about ring work?  Should we focus on long and low first?  
I believe we have had some excellent discussions earlier this year on 
just these topics.  So instead let's cut to the chase...what do we mean 
by "in a frame" out on trail, and concomitantly how do we achieve this in 
our warm-up prior to a ride?
First off...let's summarize WHY we put a horse in a frame:  improve 
balance, improve gait efficiency, reduce muscle fatigue, improve 
"forwardness", bolster the carrying capacity of the back, reduce 
concussion, improve speed and agility...need I continue?  These are 
proven benefits and indisputably the result of YOU having done your 
homework in the ring, at home.
Your warm-up must be a carefully chosen set of exercises, which have been
practiced at home until they become "second nature" for both 
you and your horse.  They must assume the characteristics of a "Mantra" 
for they will fulfill many of the same functions--to focus energy, relax 
muscles and prepare the body for work.  They need only to be simple and 
repetitive, easily recognized by the horse as a relaxation exercise, 
with limited goals, easily achieved.  What you choose, how you do it, 
are personal.  For me I like to do a free walk on long rein, making sure 
the hind end is engaged by using leg aids (see my earlier post this year 
on how to achieve an active walk), then a slow posting trot during which 
I change diagonals every 3 strides to balance both myself and the 
horse.  I do a set of exercises to position my seat bones and flex my 
shoulders (which are my tightest area in the AM)--and yes I do this on a 
bouncy horse with an awful lot of "go", and that's because I practice, 
practice, practice....
Now let's get technical.  This will come as no surprise--an Arab's "way 
of going" is a bit different, a little more "heads-up", frequently with a 
great deal of brilliance in hock action, sometimes with a daisy-cutter 
trot, sometimes with a lot of knee action.  All-in-all, an Arab presents 
a singular set of intriguing problems to achieve a frame which will 
fulfill the goals of efficiency/lessened muscle fatigue going down the 
trail.  And keep in mind that YOUR frame may be different from MY frame 
due to mechanical differences amongst these horses.
Here is what I have discovered from analyzing photos of Kevin on Mr T as 
they are going down the trail.  Mr T has a 12-14 mph trot at which he is 
most efficient.  From a side view, if I draw a line from the base of his 
jaw level back to the rump, the line passes through Kevin's knee.  This 
is the position from which this horse drives from the hindquarters, base 
wide, with a freely swinging back and his head swinging slightly 
side-to-side indicating flexibility at the poll and relaxation in the 
jaw.  When this horse stops this gentle head-swing, he invariably 
tightens up and hollows out. 
How do you know if your horse is relaxed in the poll and jaw, has a 
freely swinging back?  Put him/her on a longe line with side reins that 
are slightly loose to allow the horse to find the most comfortable head 
set and observe at several gaits/speeds just where the horse becomes most 
relaxed.  You can observe the movement of the back with or without a 
saddle--I would recommend without at first so that you may train your eye 
to discriminate softness and flexibilty from the overall carriage.  
Observe where the head set is, then when mounted attempt to duplicate 
that position by keeping your hands low alongside the withers, wrists out 
(no bunny paws here!), gently squeezing the outside rein as if it were a 
little tack sponge, while keeping an active inside leg.  When on trail 
look for a long straight stretch, preferably with fairly good 
footing.  You may first start with your long 'n low exercises at a slow 
posting trot, or a walk if necessary.  Set your breathing to nice deep 
breaths that are SLOWLY exhaled, as you work your hands up the reins, 
outside/inside/outside/inside, until you have achieved that mental image 
of a "frame" from your longing sessions.  Keep your hands low--and in 
case you are wondering how to do this without falling forward on the 
neck, the deep breathing will relax and drop your shoulders slightly 
forward/down so that this position is comfortable.  It doesn't mean 
"short reins"--you aren't in the ring.  What you will have is the 
slightest of contact (2 oz worth perhaps?) without a loop in the reins.  
Your breathing is key here....exhale very slowly, and control the speed 
of your posting, and think about invisible hands massaging the back of 
your neck to relax your shoulders.
Now concentrate on the feel of the gait...watch the ears and the swing of 
the head.  You will feel the back come up into the saddle (yes, even in a 
standard western endurance type, tho' not as dramatically as in a Sports 
saddle) and a slight lowering of the haunches as your horse begins to 
drive underneath himself.  You will be able to feel the sensation of a 
stride that is covering more ground without an increase in speed.  This 
is what we mean by efficiency.  And this is being "in a frame" for YOU.
Practice this on both diagonals and don't be surprised (or disappointed) 
if one diagonal isn't working as smoothly as another--most horses/riders 
are one-sided.  Just go back to the ring and work on your 15 meter 
circles until you feel just as comfortable on either diagonal.
Now for those of you who use hackamores, you need to be a little careful 
about establishing "contact"--hackamores can cause a horse to break at 
the poll and stiffen the neck--it looks like "a frame" but is 
tension-filled and not a pretty sight.  I'd strongly recommend doing 
ringwork with a bit (snaffle, Dr. Bristol...NO Pelhams or curbs) and in 
the initial stages of your trail lessons also.  Once you are confident 
about "your frame", then you may practice using the hackamore.
A horse simply does not desire to go down the trail "in a frame", he does 
not have the same athletic agenda that we humans do, so for him/her to 
achieve this level of fitness that enables him to compete and complete in 
CTR/endurance, it is OUR job to provide the horse not only with a set of 
skills but also with a set of muscles that will make this job 
easier/safer/enjoyable for everyone!
And these are not the same muscles you get from running them up and down 
mountains.  You need to build the carrying muscles from the belly up and 
you do this by encouraging work in a frame!
If questions, please email me.  I have a set of exercises for softening 
the jaw, exercises from the ground to soften and flex the poll, "carrot" 
exercises (done mounted & unmounted) for flexing the neck, etc.  Be happy 
to share them with you.
Diane @ Safe Haven