WHAT....did he do???

Well, I was tacking Luca up, and although he's only been under the saddle, like, 7 times, he has already mastered the skill of "blowing yourself up when the forth is being secured." No problemo, I just do it as tight as it will go when he's blown up, and then walk him towards the paddock where I ride on, he will forget all about the girth an relax, so I can adjust it properly. So...i just walked him over to the paddock and made him stand by the gate. I tightened the girth. I always use the second-second-to-last hole, so that there are two holes above it. He starter to GRAZE but I couldnt let go of the girth because I a,most had it in the desired hole. Then his knees started to buckle. He kept on grazing while it happened. I stopped tightening the girth at once and he went back to normal, still grazing, not even lifting his head. I tightened it again...almost to the desired hole....ungghhhh....and then his knees buckled AGAIN and he went down on his knees, as if he was about to lie down. I quickly pulled him back up before he Kay down with themsaddle on his back and he stood there, obviously nkt faze,pd, wanting to keep grazing. But I held his reins. And tightened the girth again. He didn't go down again amd neither did his knees buckle, amd I was able to adjust the girth to the right hole.

Now, this horse has weirded me out many times, but this time was by far the strangest. I'm kinda scared..... and I feel bad, too. Did I, like, squeeze all the air out of him? I always use the same hole and like I've said, I've only used the saddle and girth 7 times. Maybe the tightening girth pressed on some pressure point that made his knee muscles give out or something?? how tight should a girth be?? Sorry for the stupid question but seriously, that horse freaked me out....

The horse has nerves in the cinch area that if the cinch is too tight his legs weaken and he will go down. Google Endospink on youtube and see how he utilizes it with race horses. He is a very skilled horseman.

So I pulled it too tight? I think I pulled it a tiny bit too tight because once I slotted it into the right hole, he stopped.

It is very possible to have the girth too tight, especially too fast.

Why has this hole been deemed "the desired" one???

Everytime you cinch up, you need to check the tightness. Some days it may be on a different hole, because that's just how it works.

I think you were too focused on putting it where it always is.. instead of reading how the girth affected your horse...

Too tight.

If I put it one hole looser, the saddle slips to either side a bit when I ride. But yeah, I pull it tighter than the usual hole, so I can easily slip it into it. I'm also not the strongest person in the world (I'm a 13 year old girl) so I have to pull it up quite fast to gain enough momentum to get it tight enough. Maybe I need my dad to do it for me :/ or I just need to do it slower...if I can

You should try standing on a block and seeing if that angle is easier for you to cinch up. If not, then maybe you need to work out with some soup cans and build the arm strength :)

I never use the holes in the billet strap on the left side of the saddle, I don't even have holes in it.
That way you adjust the saddle however tight necessary and it is not tight or loose according to holes.
Saddles are not supposed to be as tight as possible.
I put my saddle on just a bit tighter than snug.

You might be talking about an English saddle though. Got to have holes on that one!
If you use an english girth with elastic on the near side, that helps from getting it too tight.

I try it out every time I tack him up, it's always the same one. If I do one looser, the saddle doesn't stay in place, tipping side to side when I ride. As I've said, it only goes too tight when I pull it up, because I do it too quickly. When my dad did it once, he didn't buckle his knees because (of course ) my dad is stronger so he does it more slowly.

Think about if someone would strap a belt on you and tighten it as much as they can. I'm sure you would not be happy about it. It shouldn't take very much muscle to tighten up a girth. Like you said, you're 13, not 6. Just take it hole by hole.