This clip is a pretty good example of a horse blocking. I want to
walk to the horse's right shoulder, but he is using his head and neck
to block me from approaching him on that side. Most people do not see
or recognize when a horse is blocking and therefore do nothing about
it.
Allowing the horse to block me allows him to develop the habit of
evading me and the potentially dangerous habit of using his head, neck
and shoulder to push into me, instead of yielding.
By educating the horse to acknowledge you and respect your space you are helping him and yourself make your training sessions a relaxing and productive experience. Think of it as teaching him his alphabet before you ask him to spell. Notice how I step back, rest, and praise him when he understands what I am asking.