"Horses kick for two reasons... they're afraid of you or they don't like you! That's the big, distasteful truth! Fearful horses kick in defense, dominant horses kick out of resentment and dominance. Either way, smacking the horse for it doesn't work.
You need to get the horse to where he trusts you, likes you, respects you... and none of that is achieved through violence.
First of all, stay out of the kick zone. Second, learn to "read" your horse's intent, they always give warning signs so you need to learn how to recognize them. Thirdly, give your horse no reason to kick you."
Smacking does not work. Sure it works temporarily, or perhaps only when you are around, but there are more effective ways of dealing with a horse who kicks. If a horse is kicking out of fear, by smaking her you are only proving yourself to her an untrustworthy, unpredictable, predator - not a leader. With the dominant horse kicking to get you out of her space, you're simply aggravating her. She's still ticked off, she still doesn't like you...and now she's even more ticked off towards you. A smack never earns trust and it never earns respect.
1. If your horse kicks, keep out of that area until you've earned her trust or respect!
2. If you can read what your horse is telling you and respond at the smaller phases she's giving you, she won't need to kick. A kick is an escalation of communication from the horse. She gradually escalates her "talking" from a whisper (laid back ears) to a yell (the kick) - respond to a whisper and she won't yell.
3. Give your horse no reason to kick you. Don't push her past her thresholds if she's a fearful horse, to the point where she feels she needs to kick you in self-defense. If it's a dominant kick, don't confront the horse to the point where she feels she needs to kick you. Challenge her to learn and earn her respect, but do not confront her.
Play games that earn a horse's trust and respect. Also, if a horse does kick you, do not react! To them - a prey animal, you are only proving yourself an untrustworthy and unpredictable predator if you react (ie. yell, kick, hit, etc)...just as they had suspected. Instead, remain calm, ignore the behaviour, and work to solve the root of the problem - a lack of trust or respect. Violence solves nothing and will not earn respect or trust.
An example of both dominant and fearful kicking:
One of my recent additions is an off-track Thoroughbred gelding, 5 years old this year. He would kick for both of the above reasons - out of fear and dominance, depending on the situation.
We were playing the figure-8 patter on-line on the ground and he was growing increasingly anxious, especially moving between me and the barrel; at one point, he bolted past me and nailed me in the leg. Immediately afterward, he flipped out even worse - he was positive this predator at the end of the rope was going to kill him, particularly after he had kicked it! Instead, I gritted my teeth and continued working with him calmly and patiently (continuing the exercise) until he calmed down and relaxed. He'd come around that barrel thinking he was in danger, and he was going to 'get me' before I could 'get him'. So a) I ignored his kick, proving to him I wasn't unpredictable after all, that I was still a calm, assertive leader and b) I progressed our work over the following sessions (as planned) to earn his trust. As a result, I am slowly but surely earning his trust in my leadership and in myself as a herd member, to the point where he will never feel the need to kick me in self-defense.
A dominant horse does not want to move his feet for you, he figures he's the best leader and until you prove yourself otherwise, he's going to insist on being leader. This is where it is important to earn a horse's respect and not force it. If you attempt to force it, he might react negatively and even aggressively - he'll fight. If you earn it, he will soon give it willingly. My OTTB, being a dominant horse (a Left-Brain Extrovert, as we'd call him), was not willing to simply hand the reins over to me. If I asked, on the ground, for him to move his hindquarters over (something especially difficult mentally for a dominant horse to do - to move his hindquarters submissively), he'd do it...but I'd have to pay attention to what he said. At first I had to ask little - if I asked too much of him, if he felt I was too demanding, I'd get a tail swish, a dirty look, and a raised hoof - even a kick if I pushed it. As I worked hard at earning his respect in a number of areas, he willingly gave me more and more respect. I asked little and got more. I never confronted him: if he said "no", then "no" it was. Instead, I'd focus on earning his respect differently (perhaps with a lighter phase), or from another angle - I would compromise. Now, he'll let me know if I am asking something rudely (ie. using a higher phase of a"ask" than was necessary), but will willingly give me a high level of respect and move his hind end. Our partnership is still a work in progress, as he's still a pretty new herd member, however we're attaining much, and quickly.