I disagree with the not being assertive enough thing. I don't think being more assertive will do much, other than lead you to beating a confused horse, who is clearly already lowering his head and telling you he doesn't get it!
Besides that, I have found yielding the forequarters to be the most difficult thing I train on the ground. I'm not sure why, but I either have the lead rope too short and they move but get yanked, too long and they go away from me with all 4 feet and maybe even forwards or backwards, or they just don't get it and do exactly what you are saying where they stand there.
After this happened with a few horses I started teaching the yielding the forequarters, or turn on the haunch from the saddle instead. I knew better how to use my own body for that maneuver. The horses get it, then I do it from the ground. One of my horses is worse on his left side so I often have to get on and off and practice it from the saddle and the ground until it gets smoothed out. I do this because just being assertive and wacking him isn't fair to him.
I would not expect the horse to cross over the front end perfectly at this point. That's more of honing the technique once you've established the basic concept of moving the front end away. I have seen the CA video for this, and he goes into the front leg crossing over thing too quickly, and doesn't acknowledge the little steps in between.
I would give this horse some tools to help him out. Does he know how to back up with a wiggle on the lead? You can use that as a tool to help you with yielding the forehand. You say he moves away when you lean on him, that's a tool he has already installed. Use it! Then adapt it to fit your needs, or to fit the CA style of how to ask for the yielding.
I think aprilswissmiss's idea is what I would do. But take it slowly. Do 5 min where you push on his shoulder and if he moves 1 front leg away, stop and reward him. This is your foundation for the idea. If you don't give him those little successes he will shut down like you have described. He sounds like a good horse, he is trying, but just a little low on ideas in his head for what to try next.
The next day ask him to yield the forehand using the same shoulder pressure, but ask him to move both front feet. Don't worry if he moves backwards or forwards just yet. You want him to move his front feet, so it he does that you need to reward him. Then slowly build the expectation. Go slow, and see if you can make it into a game for him. Push on his shoulder with one hand, lead in the other, and start to refine the movement. Go slow, to the point where he's only feeling enough pressure to move 1 foot at a time. Then you can better control which feet he moves.
Then day 3, refine the movement even more, still by pushing his shoulder over, but ask for him to take 2 steps away instead of just moving 1 foot or taking 1 step. Build his confidence here for a while. Make him feel like a pro! Do this for several days until he has mastered the movement of you pushing him shoulder and he takes 2 steps over. THEN you can start refining it further, and help guide him to step across the front. When he steps over reward when he crosses over the front. If he doesn't do it at first, then keep asking until he accidentally steps in front and reward. Again go slow with this new expectation. Wait until he has mastered it before moving on.
Now I'm at day 4 or 5, the horse yields it's forehand with shoulder pressure, but I want him to yield over when I pat the air next to his neck/face. Start with the shoulder pressure that day. Establish what you know, he should be really good at it by now! With one hand that has the lead rope pat the air near his face/eye, while pressing his shoulder with the other hand. You are essentially teaching him 2 cues for the same maneuver now.
Next day, like aprilswissmiss said, slowly graduate off of the shoulder pressure until he moves off the air tapping pressure. This could take several days and you need to stop to reward his effort, even if he isn't doing it perfectly. Soon you will be at a point where you can pat the air and just touch his shoulder so gently and he will move. Then try without the shoulder pressure at all. See what you get. If it doesn't work, remember you have a shoulder touch you can fall back on until the transition is smooth and he understands to move off the pressure with you tapping the air.
Then you can refine the movements with tapping the air just like you started with him when pushing the shoulder. Build up ensuring he is crossing over the front leg, more steps, quicker response, etc.
When you go to the saddle you now have 2 tools to teach turn on the haunch. You can carry a stick in your hand facing toward his face that you can tap the air with, and you can stick your foot forward on his shoulder and push his shoulder with your heel.
Sorry for the novel, hope it helps. Just go slow and reward the tiny efforts along the way, your horse will appreciate it.
Ah one more thing as an after thought... have his butt up against a fence so he can't back up.
Last edited by Filou; 06-27-2019 at 12:16 PM.