Yep. She's strung out and hollow backed alright. I start my horses lunging in just a flat webbed halter. In my opinion the knotted rope halters are a money making gimmick. Almost all green horses tend to fall to the outside when first lunged in a halter.(Any halter) I don't worry about it too much. When the horse learns to stop, trot and canter on voice command and do transitions on the line I put a snaffle on him without reins and lunge him with the line still attached to the halter which is under the bridal. Next, I attach reins to the bit. They can be made out of pieces light rope about five feet long. I use a surcingle and attach the reins to the rings at shoulder blade height or a little higher with very light pressure on the mouth. The inside rein has to be slightly shorter than the outside in order to get the horse to bend to the inside. The lunge line is still attached to the halter. As the horse gets used to the pressure on its mouth I gradually shorten the reins at the surcingle. This may be over a period of days or even weeks. The goal is a vertical face. The horse should be able to go in this frame at an extended trot and canter. When the horse becomes submissive to the rein pressure I transfer the lunge line to the bit. You may have to get after the horse at first to get it to move forward when bitted up. You have to do the exercise in both directions. This will cure the falling out on the lunge line. You next apply what you have taught your horse on the ground under saddle. Lateral flexation exercises will also help teach your horse to bend to the inside and make it more supple. Start in a 10 meter circle and shorten it until your horse is turning bent to the inside in a very small circle and then widen it again. A word of warning. If you attempt to bit the horse up without the preliminary work on the longe line the result may be a spectacular wreck and injury.
Yes she does that when I don't ask her to collect up, but she is willing to collect when I ask for it. The picture above is like the worst of the worst. Also, she already knows how to lunge (walk, trot, canter, whoa, etc) so that's not a problem. She has also already been lunged in the bridle without reins before.
Now, on to today, eliduc I took your advice and went slow to make sure she wouldn't flip out. I got out the barn today and found out that my friend actually has surcingle and side reins with sections of elastic in them that she is going to let me use as long as I need! We tacked up my mare in the surcingle, and hooked the side reins to it, but didn't hook the other end to her bridle yet.
I spent a few minutes just lunging her with the lunge line hooked to the halter, when she was moving along nicely and listening to cues I added the side reins hooked to her snaffle on the loosest setting they could go. My friend was watching just in case something went wrong, but Bourbon handled them like an old pro. After a few rounds of that with her not caring a bit, I tightened them a couple holes more to where she had super light contact with her mouth.
She was perfect
! She started collecting, bending at the pole, moving off nicely at the walk and trot, and curving to the inside. She could have cared less about the reins or anything. I'm going to keep her at this hole for a while and then shorten them a hole or two more.
Thanks so much for the advice and input y'all! I think this system is really going to work well for us! I might post some pictures later...