Science has finally answered one of the most pressing questions by people who wear sneakers a lot - why shoelaces come undone even after making sure they are firmly tied. Everybody has practically experienced this, and that's for sure, and now, scientists from the University of California Berkeley can explain the reason why.

The experts at this top university can finally explain why shoelaces keep coming untied, even after they are firmly knotted, and they have found that the repeated impact of the shoe on the floor is the cause why the knot loosens, The Sun reported.

The researchers are mechanical engineers at the university and they conducted a series of experiments where they had to film one of their colleagues in a slow motion camera while running on a treadmill. What they have discovered is that there are dynamic forces that does the untying of the knot while people walk or jog, CNET reported.

Study co-author and graduate student Christine Gregg explained that this event is not caused by the forces that is coming from a person that's like pulling on the free end, but the force comes from the inertial force of the leg that swings back and forth until the knot is loosened from the shoe that strikes on the ground repeatedly. Gregg was also the one who was running on the treadmill while doing the experiment.

Understanding this event, according to the researchers, will make sense because they said that it could be applied to other things, especially the ones that fail under dynamic forces, including DNA or microstructures, as explained by Christopher Daily-Diamond, a graduate student at Berkeley and co-author of the study.

This research will be published in the journal Proceedings of the Royal Society A.