Yesterday, Matt and Deb Hirons came to visit us at our place. It was great meeting people in the horse world who are committed to making horse more comfortable as well as their riders. They have a fantastic tool which measures both left and right sides of the horses back in relation to the spine, as well as the angles of the spine from the withers to the lower thorax. This measurement tells us if the horse if more muscled on a particular side. Matt and Deb can work with your saddle, if at all possible, to change either the tree or the flogging to adjust to the horses build. In their experience, if they can adjust the saddle to free up the horses' movement, many times the horse begins to become more symmetrical as their movement is not impinged by the saddle. They usually advise on a follow up fit in 3 months to see if the saddle needs any adjustments. I was very impressed with their commitment and expertise. Their website is:
www.mdsaddleservices.com if you'd like to check them out.