Many decades ago my parents gave me their horse, a high headed 7/8 Arab 1/8 ASB mare who did not jump. This mare had problems, and one of these problems was going around ALL THE TIME inverted, both when someone rode her and out in the hilly pasture (she had 24-7 turnout.) When I started riding her she would invert, she would bolt for no apparent reason and when that did not discourage me she would balk. I put her in a double bridle so I would have some control over the bolting and I strapped on my POW spurs to deal with the balking.
She came to me NEEDING a standing martingale if the rider wanted any type of control.
I was determined to get her to where she did not need a martingale to get her head down when moving. I hit my library, and in “Give Your Horse a Chance” by d’Endrondy (sp?) I found a technique that WORKED.
His solution was for the rider to raise their hands until the reins were parallel with the bridle’s cheek pieces and be ready to IMMEDIATELY follow the horse’s head down keeping contact all the way down and all the way back up again.
I had nothing to lose. I was horse, land and child poor and could not afford to send the mare out to training and I could not afford good lessons. I HAD TO fix this on my own. I rode her 6 days a week for one to two hours each ride.
So I took off that standing martingale which made her other problems worse. I started off at the walk in a hilly pasture (my only riding area) with her trying to bolt and any contact with the bit made her head go UP and her head stayed up with a gaping mouth as she tried her best to run away with me.
Using my legs to drive her forward I made my reins parallel with her bridle’s cheek pieces and she dove her head down all the way to the ground, and I kept contact with the bit all the way down. Of course her head came up again, so my hands went up again, I made her reins parallel to her cheek pieces again and she moved her head down by herself, until the next time she felt irritated by simply anything.
This went on for several weeks, then she finally consented to allow very light contact with my hands.
Of course her head went rapidly UP again whenever she was irritated about anything, I raised my hands, her head went down, and I got the beginnings of true contact until the next time she inverted. ALL this time this mare was either trying to run away with me or would balk, ignoring my legs totally. I had some exciting rides.
It took several months before she willingly stopped inverting all the time on contact. After the fourth month I watched her trot in the pasture and she was still inverting in the pasture, and I knew that all my good riding would be worthless until she learned that she could go trotting around the pasture without inverting her head.
So I dug into my bits and pieces of extra tack and I make up a chambon. I lunged her in the chambon three times, and then finally she stopped inverting when moving loose in the pasture.
In a few more weeks I switched from my double bridle to a snaffle bridle, got her going well in it reaching confidently to the bit, then I introduced riding on loose reins. Occasionally she would invert, my hands went up, and her head went down. Then one magic day she did not invert at all and she never inverted again while I rode her. After that she became reliable to ride on loose reins.
Since that barn did not have a riding ring or any jumps I never jumped her.
A few decades later I started taking lessons. My riding teacher put me on one of her problem lesson horses (Arab gelding) that would invert if contact was not light and steady, or if the horse thought that anything iffy was going on around him. He jumped in the lessons, usually 2’ or less. When he inverted my hands would go up until he reached out with his head to take proper contact with the bit. This horse took only around three months before he stopped inverting when I rode him, riding only in a snaffle bit with no martingale. I was riding this horse only 30 minutes once a week.
I have used this technique on other horses too.
Good luck. You have a lot of grit to keep on working your horse. Using this technique for several months you will discover that your horse can give you the rides you dreamed of when you bought him. Keep your contact LIGHT, and always follow the horse’s mouth. Forget about collecting the horse until he reliably carries you without inverting, and ALWAYS follow the horse’s mouth with your hands.