The problem: Horse backs up when he spins.
Why does this problem happen? A horse may back up in a spin if he has been backed up into the spin too much (I rarely do this – and only to correct another problem – because a spin has forward movement) or because too much rein pressure has been applied while spinning. I have also seen horses with a huge amount of ‘stop’ back a little square as they spin – one step each quarter spin – and I’m all right with that.
How to correct this problem: If my horse wants to back up too much when spinning, I turn-around once, stop him, ask him to lower his head if it is up, and walk him forward into the bridle for a couple of steps. Then I ask him to turn around once again and repeat. After several corrections like this, he might stay correct in the spin for two or three turns. If I feel him backing up again, I push him forward out of it and ask for the spin again. It may take many repetitions of this exercise to change my horse’s mind about backing up while he is spinning but, as always, consistent repetition will correct the problem.
Note: A horse that consistently backs up in a spin not only does not stay in the geographical area of the spin (thereby incurring a low maneuver score in competition) but also will probably cross behind in front and/or hit himself as he tries to cross over.