Here are some videos showing you stretches to develop better flexibility (not only) for higher kicks.
Because there is no such thing as having too much active flexibility.
Static Stretches and middle split
Standing side stretches with rubber bands
use a pulley to do standing stretches
Elevated fron splits
How to improve your splits
Simple DIY construction using a rubber band, a PVC pipe and a connector
Well, none of the videos really show any active flexibility! They show a lot of passive flexibility under resistance…
Paul is no doubt incredible! However, the asian dude has spend more time doing pushups and watching Bruce Lee movies than kicking… His kicks are fast but lack of smoothe and flexible movement – look for example how his standing leg is angled backards instead of perpendicualr to the floor or forward in angle.
HIs hams and hips seem if not tight then limiting factors. I'm indulged to say that it is a typical sign of too much forcing and not enough quality work 🙂
Good observations. Active flexibility is essential for kicks.