It isn't so much about it slipping but about slight movement with every sitting trot stride. This can irritate the horse's back. You want no movement at all with the saddle and be one with the horse.
It is tough to check when your short legged and your large pony is in a tiny girth. Making it a longer way to reach to tighten. If no one is around I will often hop off to check/tighten. He often likes to blow up and we walk around and prior to mounting. I sometimes get the girth 3 holes tighter before even getting on.
Years ago, Nick Pawlinko, Natalie Lamping's dad, taught us to move the leg forward and reach down. This after being able to touch our toes without falling off. You have a lot more strength pulling up from the saddle than you do pushing up from the ground.
I too find it incredibly difficult, as a former hunter rider. I can do it in my jump saddle with my eyes closed but I hate feeling so vulnerable doing it in my dressage saddle. I try to tighten it right before I get on, which usually works since I hand walk my horse across a pasture to get to my ring, so by then he's stopped puffing out. If it does need tightening once I'm on and someone is around, I get them to do it for me, otherwise I dismount and do it.
When I tighten mine I find that I keep my feet evenly weighted in my stirrups and my body centered (no butt over to the right). Leg goes back just a bit. It's a small girth on a wide short horse so I'm pretty much upside down while doing it. Many times I'll see stars when I sit up again!
Not sure if it would be as easy for me doing this on his right side.
Leg behind not in front but I didn't have to move my legs out of the way.
Open your hips and bend from the hips. I think if you're bending from the back you might feel like you can't reach.
He walked a bit -it wasn't a problem.
He is total garbage! Quick! Hide him on my trailer (Petstorejunkie).
You could just remember, or make a note of, what number holes you're at when the girth is tight enough and do the girth up to that before mounting. If the horse is puffy, groom the back and girth area, put on the saddle and gradually do up girth as you finish grooming.
I think part of it is I feel very vulnerable leaning over like that. I have started just walking her around the arena a lap or two before tightening one more time then getting on.
I do the same thing. My horse is girth grumpy. So I walk him around the arena once or twice, to let him sniff poop piles, etc., and take his temperament for work. Then I tighten up. But once the leather warms up and expands, I usually need to pull up one more notch.
Haven't fallen off yet. But I've been riding him for a long time, so he's used to me hanging off the side of the saddle.
__________________________ "... if you think i'm MAD, today, of all days,
the best day in ten years,
you are SORELY MISTAKEN, MY LITTLE ANCHOVY."
Yeah, I get it pretty much where I want it to be from the ground, but will sometimes find it needs to come up a hole after I mount. Leg forward, reach down and pull. Better leverage, not hard, but I can see that might be iffy with some horses. My present horse, whom I've had about 5 years now, is finally quiet enough for me to do that. When he was 3, I wouldn't have dared.
Years ago, I had a Kiefer Zugspitz single-flap dressage saddle. Fit my then horse very well. Loved it (was sorry to have to sell it when it just wouldn't fit my next horse). Had to lean over pretty far on that one, but it could still be done. I tended to keep my foot in the stirrup and push my leg BACK with that one.
Hmm.. is some of the problem you guys are having related to the dressage girth being too short?
I ride a monster of a horse (jumbo shrimp sticks over 17.2 barefoot on concrete) and I'm 5'4". I don't have a problem tightening the dressage girth from the saddle even though the dressage saddle is new to me. Properly tightened the dressage girth ends about 2 inches below the saddle pad, so leaning over and tightening just requires me to basically stretch down to about my ankle. Maybe a longer girth would help some of you out?