Biology
Joint Friction
Quick fact
Joint friction can reduce movement efficiency by up to 30% without proper lubrication.
Why this is interesting
Ever noticed how your knees feel stiff after sitting for a long time? It's not just aging—it's friction in the joints.
Read the full explanation
Understanding Joint Friction
Imagine two smooth stones rubbing together. In your body, bones are covered with cartilage and surrounded by synovial fluid, which acts like a lubricant. This reduces resistance as the joint moves, allowing for smoother motion.
A deeper explanation
Joint friction occurs when the surfaces of bones meet within a joint. Cartilage cushions these surfaces, while synovial fluid provides lubrication. When this balance is disrupted—due to injury, disease, or age—the joint becomes stiff and painful, illustrating how biological structures are designed for efficient motion.