When we hold a ten-pound object (which is less than the weight of our head), we immediately recognize the impact of its falling. We are not, however, as sensitive to our own weight.

Adult human beings weigh, on average, between 100 and 200 pounds. Gravity sees to it that we, like everything else, are always moving down to earth...falling. Our falling generates tremendous force. The force generated by our falling is either working for or against us. How we fall determines how much effort we must exert to sit, stand and move.