But toes actually play an active role in our everyday walking and running says biologist David Carrier at Brown University. For one thing, they can help us keep our balance. But, more interestingly, toes give us the chance to switch from first gear to second to third so that we can increase our speed just like a car does.
"Years ago," says Carrier, "I started wondering about toes, and thinking that toes might provide a way to change the gearing much like in a car or bicycle during the course of a running step."
In a car, if you're traveling 30 miles an hour in first gear, the engine races because the first gear is just a tiny cog wheel driving the car. But shift up and the car engine runs smoothly because a higher gear uses a larger cog wheel and a larger force so it doesn't have to work as hard. The wheel has an easier time making the car go faster.
Well, the same principle applies to your feet. When your foot is short it acts like a small cog wheel-or first gear. Put your toes down and your foot gets longer like a large cog wheel-or a high gear. If we had no toes, the part of our foot that touches the floor would always be the same length. And we would always stay in first gear.
"Without variable gearing," notes Carrier, "you would always be stuck at a single speed." Carrier examined the body's variable gearing and found that we use them like car gears too. When humans first start running, they accelerate in first gear, keeping their toes off the ground for a short foot length. Then, once they hit a steady speed, they put their toes down at the end of each stride, maintaining a long foot and a high gear.(NAPSI)