The pose in the video above is a variation on a classic runners stretch. It is a fairly intense variation if done with the proper alignment. A few weeks ago I wrote about a class I took that focused on the IT Band, a nasty piece of work in the outer hip. This band of connective tissue connecting the pelvis to the lower leg can be very tight due to muscular and postural imbalances.
We did the runners stretch in the above video in that class and I have been doing it every day since.
This variation on the runners stretch is very intense, and might even feel wrong. I am usually of the belief that the more intense something is, the more we need to work on it, until we feel nothing. For me, the goal of yoga is to feel nothing (and everything should be easy). If you chose to play around with this pose take it slow and easy and feel free to email me for some warm up poses to get you ready to take it on.
The key to getting the most sensation out of the classic runners stretch and this variation on the runners stretch is to flex the forward foot as much as possible and keep the hip of the grounded knee in line with eachother. The deeper you go once you turn out the front foot, the more the hip with the grounded knee will want to move to the outside. The same goes for the forward foot. The deeper you go forward the more difficult it will be to keep the flexion of the foot.