Osteoarthritis — the joint disease behind most knee, hip and hand pain past mid-life — was long explained as tires wearing bald: cartilage grinding away under years of load. The modern picture is livelier and more hopeful: a whole-joint process of cartilage biology, low-grade inflammation, bone remodeling and muscle deconditioning, in which loading is nourishment (cartilage has no blood supply; it feeds by the squeeze-and-release of movement) and rest, past the shortest term, is starvation.
That biology drives this hub's recurring surprises. Exercise is the best-evidenced treatment for arthritic pain — stronger muscles unload joints, and trials show strengthening programs rivaling drugs for knee OA. X-ray damage and pain correlate weakly — dreadful films with quiet joints and vice versa — so imaging words like "bone on bone" describe pictures, not destinies. And weight matters mechanically and chemically at once: each lost kilogram removes several from every step's knee load, while fat tissue's inflammatory signaling quiets.
The supplement counter here is enormous — glucosamine, chondroitin, turmeric, collagen, boswellia — and the trial record ranges from "probably nothing" to "modest, for some." We grade each honestly in the ingredient pages, next to the unglamorous program that actually moves outcomes: strength, weight, pacing, and using joints as the self-repairing organs they are.