Who Do Shoelaces Come Untied?

The shoelace knot comes untied due to the same sort of motion,” said Gregg, a Berkeley Chancellor's Fellow. “The forces that cause this are not from a person pulling on the free end, but from the inertial forces of the leg swinging back and forth while the knot is loosened from the shoe repeatedly striking the ground.”

Why do shoelaces come untied?

Researchers at the University of California, Berkeley wondered why shoelaces seem to come untied so suddenly. In a new study, they found that the repeated impact of a shoe hitting the ground when we walk or run loosens the knot. ... That force makes the knot stretch and relax more than it would during walking.

Why does my left shoelaces keep coming untied?

First, the impact of the shoe on the ground loosens the knot. With the knot loosened, the whipping of the free ends of the laces — as the leg swings back and forth — makes the laces slip. ... The researchers also have some advice to keep shoes from coming untied. It's all in how you tie the knot.