Hi Barrel Racer, first I would say to keep your horse in work,just so long she is enjoying it and doesn’t get extremely fatigued doing what you do. Just like humans,it is important for horses to stay active in order to be healthy. I have been taking care of my horse homeopathic-ally for almost a year now, and have learned a lot in the way of how their bodies work. Have you ever thought about your mare maybe having arthritis in her injured hock? As far as the hock injections go, do NOT do those. Her body doesn’t need that sort of thing to deal with, what it needs is something it would know how to use. Which is where herbs come in. My sisters horse in her mid to late teens and we recently put her on an herbal arthritis supplement. It has helped her significantly with her stiffness. I would highly recommend going to Naturalhorsenetwork.com and looking around at the products they have. It has been my go to place for everything horse supplement wise. You can also email the lady who owns it and ask her any questions you may have about your horse. She’s super helpful. Also feel free to ask me anything, taking care of horses as naturally as possible is a real passion of mine!