Researchers from the University of California, Berkeley, USA, explained why the laces are often untied on the go.
To do this, scientists have recorded exercise on a treadmill. The video was viewed in slow motion and analyzed.
Physicists have found that while running, the foot hits the ground with a force of seven times gravity. This leads to stretching and weakening of the tied node. At the same time the force of inertia acts on the free ends of the laces, untying them completely.
According to scientists, the understanding of how dynamic load affects the nodes, it is very important, because the nodes are everywhere from DNA before shipping and parachuting.
Previously, scientists have figured out why men love sports more than women.