The Squash and Stretch technique is to help make a piece seem more natural, more life-like. The technique basically applys simple physics to the animation piece, it gives it volume and dimensions to a flat piece of work. Taking the classic example of a bouncing ball if we never applied the squash & stretch motion to the bounce of the ball then the movement would seem rigid and unnatural. However when we stretch the ball as it lands, squash it while it hits ground and stretch it as it takes off again then we can clearly see a more natural, fluid movement of the ball.
Walk cycles need to be done right so to create a decent animation piece. Observe someone how they walk, they don't stay rigid, heads staying in the same place. As a person walks the entire body is moving; arms swing back and forth, the legs(obviously) moving and the torso and head are constantly slinking up and down. If all these matters are addressed then there is no doubt your walk cycle should look realistic. The image to the left shows a basic but accurate take on the walk cycle. Below is a first attempt of walk cycles i tried about a year back. I looks ok, the body seems to be like jelly but atleadt there isn't the idea that he is simply gliding across the screen.
