The science of shoelaces

On Sunday around 35,000 people will pound the streets of the British capital as they compete in the London marathon.

But how many of them I wonder will have properly tied their shoelaces?

Ian Fieggen, self-styled Professor Shoelace says that runners in particular suffer more than most when their shoelaces come undone as tripping on an untied lace while running can be disastrous.

Mr Fieggen has written an entire book on tying the perfect knot and has his own dedicated website.

First broadcast 24 April 2009