Hitting a little road block here with my Paint. She responds to the bit in motion appropriately, I am satisfied there, always room to improve, but what I can't do that I feel I should be able to is that I can't back her without my leg. I don't want to use my leg to back her. Why? I want the cue to be simpler, her response to the bit more accepting overall, and remove the confusion with the leg cueing; now that we do lateral exercises, she tends to move sideways or go to turn on the forehand instead of back up straight if I use my leg.
Using just my reins today, I closed my hands at a halt; she lowers her head and looks on the vertical, expecting to stretch down (only rein pressure at a halt usually was our time to do that). I hold the pressure and wait. She licks and chews, then tucks in more so I have to move my hands back to keep the same pressure. She jerks her nose back up in frustration after a second and scoots one leg back, so I release then. I kept trying this, and found that she stopped lowering her head and licking the bit when I pressured, instead ignoring my hands and sometimes taking a one small step back, but only with her nose out and clearly not accepting the bit at all.
So it looks like same pressure until step back only results in her becoming unresponsive and tenser. Some months ago I would practice closing my hands and waiting for her to lower her nose and get on the vertical, releasing every time she moved the right way any slight amount. So it would seem that if I just do that again, she will only get better at going on the vertical with rein pressure and stretching out from halt, but nothing to do with backing!
How do you teach a horse to back up on rein cue only, accepting the bit as they go?