you know I heard a story about that.. watch him because they are notorius for getting spinal problems because they are so happy and bounce around so much. He may have put damage may be catching up.
Hip Displaysia. It's common in Boxers, and can be treated, although it will never go away fully. It's a good idea for Boxers to be on either a Glucosamine and Chondroitin supplement, or on a food that contains a decent amount of these supplements.