You do not want to Drag a horses head down using side reins or any other rein for that matter
I don't want to drag his head down but he has racing muscle and for him to comfortably work rounded or on the bit etc I need to extend the muscle he has, up another inch towards the top of his neck. They trained him the cheap way to get him to look pretty for prospective buyers, but when they took him off the track they immediately worked on getting him rounded without looking at his neck muscles which are clearly defined in his neck.
I would only use them after
I have been taught face to face how to use them, and only
to get him to drop his head, I want him to work long and low to stretch his neck and back and once he gets the idea of dropping his head I won't use them for that purpose anymore.
You should NEVER Ride in Side reins or a bungie.
I won't ride in them I promise you that, if I am to use them I will only be lunging him with them on. I do ride with a running martingale (only occasionally if he is having a "oh lets be a giraffe" day, and on my mare that rears)
You need to push a horse UP between your leg and hand so that he tucks his back end under, powers from the inside hind leg, brings his back up and round and lifts his wither.
Yes he has the problem where because of the "pretty training" they taught him to be on the bit all the time, but forgot about teaching his hind end to be underneath him, so he is lazy with his back end... Hill work here we come.
He is still learning all the commands though as his last race start was april this year and I have only just gotten him this month.
I'm going to get him to bring his hind end under properly before I think about long and low or bit work or anything like that.