What If Your Joints Aren't Wearing Out?

Longish article at the link

https://drlauriemarbas.substack.com/p/what-if-your-joints-arent-wearing


here are a few paragraphs
----

If osteoarthritis were really caused by mechanical wear, then the joints under the most physical stress would always be the ones that break down first. And people who use their joints less would be protected. Neither of those things is consistently true. Something else is going on, and understanding what that something is changes everything about how you prevent it, slow it, and in many cases improve it.

---
Your cartilage faces a similar challenge. Unlike most tissues in your body, cartilage has no blood supply. There are no tiny arteries feeding it oxygen and glucose. Instead, cartilage is nourished mainly by synovial fluid, the slippery liquid that fills the joint capsule. Joint motion and loading influence how well that fluid circulates, how the cartilage cells themselves respond to mechanical signals, and how well the surrounding muscles support and protect the joint. When you walk, bend your knee, or push off with your foot, you’re keeping that entire system active. When you stop, the system slows down.

Movement is the current. Your cartilage depends on it.

This is why the “wear and tear” story gets it backwards. A certain amount of regular loading doesn’t destroy cartilage. It feeds it. And when you stop moving, when you rest a joint because it hurts, when you sit for ten hours a day because that feels safer, you’re doing the biological equivalent of putting coral in still water.

Researchers demonstrated this in a striking way. When they removed all mechanical stress from mouse joints, inflammation in the joint lining appeared within three days. Scar-like tissue buildup and cartilage breakdown followed. But when they restored both motion and weight-bearing load, the cartilage changes improved. Motion alone wasn’t enough. The joints needed actual loading to recover. Animal models like this one don’t prove that sitting too much causes OA in humans, but they show how strongly joints respond to reduced mechanical input.

---

https://drlauriemarbas.substack.com/p/what-if-your-joints-arent-wearing