Watch: Science explains it's physics, not your clumsiness that unties shoelaces

Scientists have discovered that the combined forces from legs swinging and feet pounding the footpath create a perfect lace-loosening storm. This proves that physis, not clumsiness is the main reason for perpetually untied shoelaces

As per reports in Science News, mechanical engineer Oliver O'Reilly of the University of California in Berkeley and his colleagues sought out do understand the physics of shoelaces. 

With a high-speed camera, they filmed a runner on a treadmill, catching loosening laces in the act. Using a pendulum with weighted laces tied on it, the researchers mimicked the forces of running or walking to study the phenomenon in a reproducible way.

Two effects contribute to shoelace knots unraveling, the scientists determined. "Each time the runner’s heel hits the ground, the knot stretches and deforms, loosening it. Then, as the legs swing back and forth, the laces’ inertia causes them to whip around, pulling on the free ends. As a result, the knot slowly loosens over several minutes, before rapidly coming undone in one or two footsteps," the report said.