I am hoping some of the more experienced drivers might be able to help me. Bear with me but I am going to give a little background info. My boy is turning 4 tomorrow and has been driving less than a year. Had a handful of hitches last May but didn't really start driving him until June. He did well for the most part at the few shows I drove him in last summer and fall. I let him have a couple months off to recoup from the show season and relax and be a horse. Beggining of December I started lightly playing with him again. Took him to his first parades and started working with him on driving obstacle as it is my goal to show him in that this year. Well I was so busy focusing on teaching him and myself how to do the obstacles that I let his collection and headset slide. It was pointed out to me recently and so I have been working on that. He can be stubborn so it has taken awhile but we are finally close to where I would like him. Problem is he has started fussing with his head. It is an up and down motion. He gives quick jerks of his head sometimes small and sometimes large. He does this frequently the whole time I am driving him and only slows down somewhat but doesn't quit by the end. He was not doing this prior to my reteaching him collection and headset. He never did this when he was taught the first time around. I have ruled out his teeth as the vet was out 3 weeks ago to give him shots and I had him check. They were fine. He is driven in a simple snaffle and he never seemed to have a problem before with this bit, always went well in it. I don't usually use a martingale on him and since he is a WCP horse is driven with a loose sidecheck so he has to pretty much carry himself. I have paid extra close attention lately to make sure to keep steady hands. I am not sure why he is doing this or how to fix it. Please help!!!