So this was a Challenge on GWR Challengers

https://web.archive.org/web/20130417203240/http://challengers.guinnessworldrecords.com/challenges/160-fastest-100m-run-qwop-flash-game

As far as I can tell the Challengers site was discontinued. I couldn't get the videos to work until one suddenly appeared.

It was listed as 51 seconds but might want to be retimed...

Here are the other runs listed as 51

They have a different URL but seem to be identical.