Favorite Hip flexor stretch?

[snapdragen]

Look at that YouTube video.

Can't right now - youtube not allowed at work.

Warrior 1 & 2. Make sure your front foot is as far forward as you can balance with the knee directly above the foot (so make sure the knee isn't coming forward of that foot)...you'll get a good stretch through the opposite hip flexor.

That sounds too close to a lunge position, those aren't allowed either. Bad knees suck.