Walk This Way!

Would you believe that you carry around at least two second-class levers with you all the time? Your ankle is actually a lever, and it helps your little feet move your much larger body. The picture at right shows where the fulcrum, load and effort are located. Can you see how these match up with the picture from yesterday's post?

Stand up, and pay attention to how your weight feels on your feet (this will work best if you don't have shoes on). You probably feel the weight more or less equally below your toes (the ball of your foot) and on your heel. Now lift up your heel so that you're on tiptoes. Go up and down a few times. When your heel isn't on the ground, all of the weight rests on the ball of your foot. You make an effort (green arrow) to lift your body (blue arrow) up, and the ball of your foot (red arrow) is the fulcrum, the point that doesn't move. Now just walk around, and concentrate on how your ankle works as a second-class lever.

So, had you ever realized that parts of your body are made up of simple machines?!?