After seeing these functional flexibility hurdle drills in a University of Iowa strength and conditioning video I was surprised to see them being used by Real Madrid, Real Madrid again and AC Milan.
According to the University of Iowa video, functional flexibility drills “develop the athletes ability to move through an active range of motion, preparing the body for more strenuous activities”. I need to investigate more about them, how often to perform them, at what periods in the training cycle to use them but they are obviously important if 2 of the biggest teams in world football have incorporated them into their training regimes.
This article suggests 2-3 times a week after your warm up to improve mobility.
A comment in this article on hip mobility claims they improved hip mobility by performing hurdles 2-3 times a week but this is anecdotal.