Ok, so I've been looking at some R.L. Burnside tunes and I've been trying to figure out his strumming. He gets this really percussive sound out of his strums, but I'm not quite sure how he's doing it. The two things I was thinking are as follows:

A. He's doing the strumming with his thumb


B. He's doing it with his index finger

But I can't really tell what's going on there... here's an example:

Any thoughts on how this might be accomplished? Also, any thoughts on how to play Burnside in general would be appreciated...

I know it is quite some time ago. I am looking for the name of the techniques used by Burnside in his songs. Were you successfull in playing them?

For exemple, I am looking for the name of the technique at seconds 0:15-0:17 of this very original song:

This guy is amazing.