Thanks for all the advice! Rusty is somewhat slab-sided, so it is harder for me to get my leg on him. My posture is awful even unmounted (lol) so sit-ups sound like a plan. Any other posture exercises? Also, I have been experiencing lower back pain and I guess it's because I arch my LOWER back too much, so I'm trying to figure out how to roll my shoulders back without overarching my lower back (this is what my chiropractor said).
Also, anything about Rusty? We're currently training for the hunters. I'm so proud of him as he has come so far. When he first started, he would "hang" on the bit, even after he was in shape. He honestly thought he was supposed to drop his head because he was trained by his old owner to do so for WP, but he didn't have the gait. Anyway, we switched to a pelham bit (don't worry, I have both sets of reins now), and it's working fabulous - no more hanging! Also, we had a problem with running out, and now he's game for anything.
I guess I'm asking: Where do you think his strengths lie, what should we work on for him, and do you think he would make a good hunter? I'd like to try eventing with him a few years down the road, depending on where I go to college next.