Checking The Girth
It is crucial that the saddle is securely fitted to the horse - if it comes loose, so do you!
In your early lessons your girth will be checked by the instructor before and after you mount and then again after a few minutes of riding. It is so important that being taught how to check its security from the ground and from the horse's back will be one of the first lessons you'll get.
Let's look at the basic fixing of the girth to the saddle.
You can see that this saddle has 3 girth straps to choose from. Depending on the size of the girth you should use the first and second strap or the first and third. Whichever you choose make sure it's the same both sides.
Have a look at the girth and straps to make sure there is no damage, cuts in the leather or faulty buckles that might come undone. If in any doubt, ask.
Whilst resting between lessons the girth will have been slackened off. It will need to be tightened before mounting. This can be done in the loose box just before leading out to mount or just before you actually mount or both.
Many horses develop the trick of puffing their chests out when they feel you try to tighten the girth. In this case in the short distance from the loose box to the mounting block you might find you can take up what you thought was a tight girth by another hole or two.
You might need both hands to pull tight the girth and pop the buckle in - so how do you hold the horse and stop him wandering off? With the reins placed over his head slip your arm nearest his head through the reins so that it catches in your elbow. You then have the use of both hands and a hold on the horse.
The girth is tight when you can just slide a hand between it and the lower belly of the horse. Make sure that the buckles are level i.e. they use the same holes on each girth strap (count them to check) else they might pinch the horse's skin. Also check that the girth is evenly fixed on each side and not using the bottom holes on the left-hand side and holes near the top on the right-hand side.
Saddles often have a buckle guard fitted which is a semicircular flap of leather which is fitted to the girth straps and is pulled down over the girth buckles to prevent rubbing and wear to the saddle flap.
As a cautionary note; watch out for the horse that either tries to head butt or nip you as you tighten the girth. You may not think they can bend their heads around that far to reach you especially as you have such difficulty trying to get them to bend even a little when riding - but they can! A sharp spoken rebuke usually works.
Taken From New Rider