@nony - Yes, the function of cartilage includes both support and increased mobility.
It’s strange, actually; while doctors understand and acknowledge the role of Glucosamine in cartilage and joints, they don’t usually believe that the supplements can do much help. Supposedly the only evidence that exists is anecdotal and they say there are no double blind studies that prove it works.
I can’t make sense out of these contradictions, only to say that, like you, it should work at least in theory. The only thing I would wonder about is whether you need a supplement or would it be best to try to get that nutrient from natural foods alone.