system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: Why are flat feet generally worse than arched feet, when you have more surface area making contact with the ground?
gpt
The arch shape acts like a spring. In flat feet, there's not much room left to flex. Without that shock absorption, more strain is put on joints through the ankles, knees, hips and into your lower back. Not a lot more, on the scale of things, but with as many steps as people take it adds up.