When I was young, riding dressage and working for one of the U.S. World Cup riders I saw horses in nosebands fastened incredibly tight. How tight? So tight that a very dense foam pad was added to keep the noseband from making a permanent indentation in the horse's face, and, I was told, so that it could actually be pulled tighter. I wondered what could possibly be beneficial about this for the horse, and whether the horse could still think and respond with that much pressure on his head.
Now someone has come up with a way to that measure pressure and damage. Although they are just beginning their studies, the results are fascinating. See for yourself http://www.thehorse.com/articles/32369/researchers-measure-horses-noseband-pressure . After reading, I was delighted to see that at last there is scientific support for the theory that a tight noseband is actually damaging. (Something that anyone with any common sense who can apply the concept that horses are thinking, feeling beings would instantly conclude if they thought about applying a similar type of device and pressure to their own head and trying to do anything active.)
The thing about the study and the current state of horsemanship that is disturbing is that such a large percentage of the riders studied were applying the noseband tighter than what is comfortable and functional for the horse. Where is the disconnect from the horse's comfort? How can intelligent riders ignore such an obvious and simple action which is causing horses pain and disfigurement? And for what reward? These are questions we should all ask ourselves the next time we bridle up our horse.
