What to do if a horse continues to kick and stomp while trailering?

This is common with barrel horses it seems. My friend used kick chains with great success. Research them on Google and I've added a link below of them. They aren't harmful but stop the kicking and eventually break it altogether. You can also buy sideline hobbles that you put on them when they are already in the trailer. It allows some movement but no kicking. Also adding an unbreakable mirror and small salt lick or secure toy alleviates boredom.