That one is one of the one's assigned by by ted. Looking at the video it is clearer to see how imortant it is to get the right forearm lined up before you do it and start at impact fix.
If you have trouble seeing the videos what I do is right click on the video you want to watch and select target. This will download the video and then you can watch it direct from your computer when you want to watch.
Threaded Mode
