I must admit, I'll be standing on my soap box for this one.
Too often I see owners and riders enter a forum looking for a quick solution for a serious behavioral problem. 99 percent of the time serious behavioral problems are caused by pain.
There is no way around it. I completely understand searching for advise and new opinions - if I didn't I wouldn't enjoy a forum!
BUT, please know that assuming and saying "I think" my horse isn't in pain is not good enough. If it cost having a vet perform a full exam - pay it.
Have a professional assess the situation and know FOR SURE there is no pain. It is each owner's responsibility to ensure their own safety and health and secondly, the safety and health of their horse. After knowing fully there is no reason for pain, by all means, continue to correcting the horse's behavior by training. Fully examining your situation and eliminating the possibility of pain will lead to a successfully trained horse. A horse in pain will not perform to his/her best ability, and most importantly, the horse will not enjoy their job. Be a good owner, find the cause rather then a quick fix.
A good horse owner is someone that CAN stop and look at the finer details and if there is pain, they will eventually discover it.
Also, this is in no way, an attack on ANYONE! I'm just concerned for the horse and the owner's well being.