Anything that I could do for my 14 year dog; I think that his hips are starting to bother him?

His last vet visit, the vet said that his hips were fine. That was March of last year. I give him Glucosamine and Chondroitin for his hips (dog treat), daily, but, I have noticed that he curls his back end under more, and he doesn’t move as quickly. His back legs shake, but, they have been like that for a few years.

His next check up isn’t until next March, but, I may take him in earlier than that.

Is there anything else that I could do in the meantime to help him with his hips? Maybe, a heating pad set on low for his dog bed?