Thank you for your question, Ashley. I am a bit concerned that your horse may not be feeling well. When we see drastic changes in behavior that cannot be attributed to a particular event (such as something very painful or scary occurring), medical causes are often the culprit. You mentioned that he has a little arthritis in his hind foot. It is possible that this condition has become more painful for him, or that he has developed other physical issues. I strongly suggest a thorough vet exam.
Did you punish him by yelling or becoming physical with him when he attempted to kick you? If so, it is possible he has become fearful of you. If his vet exam clears him of any physical problems, I suggest teaching him to stand still for a food reward. You can begin this with him in his stall and you right outside. First, teach your horse that a particular sound or word means that food is about to come. I like to use a short whistle sound that I can make with my mouth. Make the sound (let’s call it a “tweet”), then give him a small tasty treat. Once he is anticipating a treat when he hears the sound, he is ready to learn!
Now, wait until he stops walking about his stall—tweet and treat! Soon he will learn that standing still results in a tasty treat. Now you are ready to give this behavior a name; let’s try “Steady” (more common in the elephant-training community, but an easy, distinct sound for your horse). Give the cue “Steady;” if he becomes still, tweet and treat. When he is consistent, try the cue while he is on cross ties or in his stall. He will pick this up quickly. Once he does, be sure to do things that feel good while he is standing still, like grooming or giving a healthy scratch on the crest of his neck. Teaching your horse to stand still is really no different than teaching him to canter or anything else. Patience, positive reinforcement and verbal conditioning will work wonders.