Some exercises on and off the horse. I still, 10 years into dressage, have difficulties tilting my pelvis forward. I have a natural arch in my lower back which results in my butt sticking out. It also, I think, contributes to some lower back pain when I have to do alot of standing so I am thinking about visiting a doctor. Just not sure if this is a chiropractor thing or an orthopedic doctor issue.
One thing I have discovered though is I think I have been fighting my saddle for the last five years. Really sucks because I bought the saddle brand new through a saddle fitter and bought it to fit me and the horse. I just didn’t know enough and hadn’t sat in enough saddles to know that it was wrong for me. Rode in my friends saddle (Albion Style SL)which apparently has a narrower twist, and low and behold, while not beautiful, I could actually sit a lengthen. My saddle apparently has a slightly wider (but not wide) twist, well according to VTO anyway (Prestige Galileo).
So I am sure that the saddle didn’t help but I know I have this natural inclination to tilt my pelvis back anyway so can’t blame it totally on the saddle.