LOL, got it walkinthewalk! Will get the vet to check those areas. He may have some stiffness/joint pain. Yet he galops and prances around the pasture with his tail up high like a foal and sails over jumps like there's nothing in the world he likes better, so it can't be too severe. Either that or he just has a heart that won't quit - typical Arabian! We do have him on a glucosamine supplement on the advice of the former owners. They said it was preventative, but who knows. They seemed very honest and forthcoming (I have his entire medical history from the time they owned him and talked to their vet as well as having him vetted by my own), but even the best sellers will sometimes "omit" certain things.
And yes, greentree, he has a "good side" when he's ridden too, so he clearly favours one direction, but that doesn't mean he doesn't have to do both! I always make sure he does everything in both directions. With lots of work, the differences between going left or going right are diminished.