Originally Posted by Oxer
there is no competent jumper rider on this planet, that sets out to restrict their horses head, neck, and ultimately their jump. I say the word competent, because there are plenty of ill trained and incompetent jumper riders out there.
With that being said, if a Prix level rider was "restricting" their horses jump in any way, they would cease to be competitive. So what you may think is restrictive, may simply be the way the horse has to be ridden. If I jumped my horse on a loose rein, he would immediately think that I dropped him. He jumps his most confident when he feels like someone's in the drivers seat!
This. Also, a lot of upper level horses need to be "packaged" to effectively use their body at that height. Not restricted, but they can't be strung out otherwise they can't properly use their hind end to push off the ground. That's why many jumpers go in more of a dressage frame, they're more on their hind end to get a better quality canter, and balanced for a good turn. I'm showing a jumper right now that can fling himself over a 3" jump strung out on a loose rein but if I want him jump higher I need to power him up to the jumps and get him in a stronger canter.
Although, you will see some people who probably are trying to either control or balance their horse and simply can't, and they ARE restricting a horse's head.