Marginalium

Why do humans double-bounce when they walk?

walking this way would have given early humans an edge in persistence hunting—pursuing animals until they surrendered from fatigue. Our flat feet and heavy legs aren’t optimized to let us move as fast as four-legged sprinters, so it’s possible that our gait pattern evolved to grant us an advantage for distance, not speed. Because the second bounce catapults the leg from the ankle, rather than powering its swing from the hip, the motion uses a lot less energy, allowing our ancestors to stalk prey for hours or days without needing to recover.