When you go in for your physical describe to them just how you have described to us, what is going on.
I have fibromyalgia, and compression fractures in my back so somedays, while riding is still amazing, it can hurt! Bad joints, all together, run in my family, so it's no surprise that alot of posting can make me sore, too!!! There are various pain management things you can do for those though, so make sure the docs don't skip out on anything...you could have anything from early onset osteoarthritus, to vitamin D deficiency.
"The ideal horseman has the courage of a lion, the patience of a saint, and the hands of a woman..."