I use back-up a lot in my training. It makes life convenient both on the ground and in the saddle and it provides a useful starting point for correct carriage and for releasing the poll when a horse is carrying a lot of brace there. I have two main ways of approaching this.
The first way is to ask by squaring up in front of the horse making direct eye contact and stepping towards them. If they don’t move back ( many horses don’t the first few times ) I make enough fuss that they decide that being around me is a non-awesome thing to do and take a step back. If in doubt I make more fuss rather than less because when one is ineffectual it tends to mean that one is teaching the horse to ignore one’s own cues. I would rather the horse overreacts a little and I can tone down my cue next time than that the horse doesn’t react and I have to pick things up next time. The big thing I never do in this situation is to shake the lead rope under the horse’s chin. I try to keep that really steady. I definitely don’t want the horse to throw their head in the air and shaking a lead rope really contributes to that, also it can be ineffectual as that is below where the horse is looking if their attention is on you. I will normally slap the tail of the rope against my chaps to make some noise and energy but you could also wave your arms around, jump up and down, just do whatever it takes to get a change. As soon as the horse steps back all pressure is off and you give them some thinking time. Then you set it up with the more subtle cue again. If you have to go beyond that more than a couple of times you are not making enough fuss when you make a fuss. If you stop making a fuss before your horse moves, you’re teaching them to ignore you. I want my horse to think they are training me not to be crazy and annoying, that way they may buy into the process a little more.
I mention that way of backing a horse up first because that is the back up that I will use in day to day life- if I am going through a gate or we get stuck on a track while I’m leading, that is how I will back my horse away. It also is what keeps me safe if the horse is anxious because it is a big part of teaching them not to run over you.
When I am working towards riding, I have a second cue. This starts standing beside the horse’s head and I hold the lead rope in my hand with the thumb pointing down and ask them to lower their head. I just keep the pressure there until they offer any downward movement then release it. This is a great exercise for teaching the basics of pressure and release. If they really resist and brace in the poll I might slowly rock my hand left and right so that they have to resist both a vertical and lateral movement. That is difficult so they tend to give after a little while. I might work on this over a few sessions as part of our basic work, until the horse can lower their head on demand and keep it lowered – often they will first offer a kind of nod, so once they are starting to drop their head one needs to ask for a little more time. I am looking for a head lowered so the poll is roughly level with the wither, so it’s not super low, just at a level the horse would hold it when relaxed. Once I have that, with my hand in he same place I will ask the horse to bring their chin a little towards their chest. This process is normally a little like the original lowering, but once they figure it out you can ask them to bring their chin back a little and they will probably step to release it. If they don’t, just wait for them to come through and maybe make a little noise if their feet are properly stuck. The moment they move, you immediately release the pressure and give them some thinking time ( of course you give the horse thinking time after every significant release, which should be close enough to every release ) after a little work you will find that by asking back with a light release for each step, you can get a lovely smooth back up with the horse’s head in a good position. In my experience this is very easy to transfer to the saddle and because you have already worked around the braces that most horses carry, it can be a starting place for working on softness in the poll and neck.
I have one other good technique too, working from the saddle. If you have a horse that responds well laterally to your leg, you can start in the saddle by setting up your body in the position for backup ( opinion is divided on what is correct and it seems that as long as you are consistent, it doesn’t matter too much ) and have the rein ready to close the door to forward, but don’t pull back, just don’t allow forward. Then ask the horse to step their back end to the left, then to the right, then to the left until they get a bit irritated and step back. Immediately release all pressure and tell them what an awesome horse they are. After a minute or so, set it up again. The advantage of this is that you get a back-up that starts from behind and pulls rather than a push from the front feet. You will know when you feel it because it is unlike what you are accustomed to.
Remember if you are working on this that back-up is a two beat movement and that horses can back up fairly quickly. Watch for loss of straightness ( often caused because you get one foot stuck ) and don’t ask for too much too soon. Once you do start to get it, however, you can use step-by-step release to encourage the horse to keep backing up for as long as you want. Horses can back up way faster than most people ever ask them to, there is no harm working on varying the speed as well as the distance that you ask your horse to back up. If your horse starts bracing on you, it would be a bad idea to release until they quit, though that can mean waiting them out for a few strides. Persistence will be rewarded in this- it is an area of training where a little work gives a lot of benefits.