People tend to think of the feet and legs as a lot of levers and pulleys that, through muscle contraction and extension, drag the body across the ground against the pull of gravity. It all seems so energy demanding. But it isn't, if you do it right!
This lever and pulley model is way out of date now that we have the work of people like Tom Myers, Art Riggs and James Earls, all sorts of models are suggested to help us get our head around the biomechanics of walking. The way I describe it to clients is this... (Excuse the oversimplification professionals but..)
Think of a soft foam ball. It can contract and absorb impact - you can squish it, it can lengthen - you can pull it and if you drop it - it will bounce, but not very high. Then think of one of those denser rubber balls that rebound straight back at you when they hit the floor. As a child I called these 'super balls'.The muscles and fascia and all the other stuff in your legs change tension during the mechanics of walking, they morph from one state to another so that after your foot hits the ground your legs become the super ball. In this way all the energy of the foot striking the ground is stored in the tissue to create a fabulous energy efficient rebound while also reducing the stress of that foot strike impact on the upper body. The signals for this change are created by your nervous system monitoring the movement in the joints and the contact with the ground below.
For this reason it is important to allow your body to move correctly, freely. Otherwise energy is lost, muscles have to work harder and you become tired and sore. This of course brings me back to my old favourite subject of bare feet or minimalist shoes that allow your feet to move naturally. Because the whole process starts when the foot strikes the ground.
