Learn how saddle fitting and horse behavior under saddle, are intimately related

This quick article is a must read and shows how your body affects your tack as well as how it can impede and even cause pain for your horse. Fascinating information when considering saddle fit and horse "problems" under saddle - most likely they are caused by either your body or your tack. 

http://www.equinechronicle.com/riding-and-training/saddle-research-uncovers-new-theory-in-asymmetry.html