When we use positive reinforcement to train new behaviours, we often do so without the use of pressure.
The behaviours are often taught via targeting, free shaping, or Luring, so the initial cues end up being hand signals, verbal cues, environmental antecedents etc.
But sometimes you may want to change your initial cue, to a more convenient cue, or a more universal cue.
This can be turning a hand signal to a voice cue, or even a pressure cue that can be used similarly to a traditional pressure and release/R- cues.
Especially for riding pressure cues can be useful.
But how to we take the horse walking forward on verbal cue, to a leg pressure cue?
By transferring the cue!
Once your horse can do the behaviour consistently on cue, and you have decided on a new cue,
Present the new cue and immediately follow it with the old cue. Your horse will do the behaviour and you will reward that. After enough repetitions, your horse will predict that the old cue will follow the new cue, and start doing the behaviour on the presenting of the old cue. Voila! New cue is established.
Taking the walking forward as an example.
Your old cue is the verbal cue “walk on!”
Your new cue will be the leg pressure (which at this point won’t mean anything to your horse just yet)
Step 1. gently press your legs on your horse.
Step 2. Say “walk on!”
Step 3. your horse will do the behaviour.
Step 4. Reward!
Soon your horse will start walking when you put your leg on, because they will start predicting that you're going to cue the behaviour when they hear your new cue
This is also how we can use pressure cues without having to utilize negative reinforcement/pressure and release! The importance is just that the behaviour was taught via Positive Reinforcement first.
Some riders don't care to have pressure cues, but alot of people find it convenient, as most of us already are used to them from our traditional riding backgrounds. Plus, if anyone else is ever going to ride your horse, it means they will be able to understand what the rider is asking them if they do end up using leg or rein pressure.
That being said, you absolutely are not required to transfer your cues. Sometimes it is useful, but often the first cue is just as effective and easy to use, and there's no problem just sticking with that one! Do not feel like you have to teach your horse pressure cues, just because that's what other trainers are doing!