Elbow Strumming is a technique used to hammer on a section of notes in a song using usually two hands for the button pushing. When there is a section of a song that usually tends to be harder coming up, you can start the sequence with both hands already on the buttons, and hit the first note of the sequence with the elbow next to the strum bar, and play the rest of the hammer ons. this is more commonly seen in songs like the intro of Through the Fire and Flames (Video) and One from Guitar Hero III and the solo of Jordan from Guitar Hero II : (Video)