Question

What are 2
factors that prevents joints from rubbing and wearing down your bones

Answer 1

The way joints are made, they naturally should not have trouble with west and tear. The other factor is the cartilage which acts as a kind of shield for the bone and this keeps you from getting arthritis unless you are unhealthy

Answer 2

a layer of smooth cartilage at their ends, which cushions the bones and prevents them from rubbing directly against one another. The whole joint is also enclosed in a synovial capsule, which is full of synovial fluid. The synovial fluid acts like the oil in an engine, lubricating the joint and preventing the cartilage from becoming worn down.