As the man walks, each foot strike creates a noticeable vibration that travels up through the lower leg immediately after ground contact. Because the concrete surface is rigid and does not deform to absorb impact, the force is transmitted back into the body, producing a brief oscillation of the soft tissues and muscles of the lower leg. This visible vibration reflects the body's response to the impact forces generated with each step on an unyielding surface.

This podcast on my book, Think Up, Lean Forward, walks you through from theory to practice of walking with less stress on the body, especially the joints. It links back to first learning to walk using gravitational torque to fall forward. Falling down created a fear of falling that changed the way most of us walk for the rest of our lives.