So my coworker caught me doing pull ups one day. He said that I was kipping. I simply told him I was not and all the force was coming from the pulling in my arms. Im a foot taller than him at 6'4" which requires me to bend me knees back so my feet don't hit the floor. Doing this i think creates a mini pendulum effect but I am not kipping! I started with 18 pullups consecutively. The vid im showing has me doing 10. This was following the recon ron pull up workout.
http://www.youtube.com/watch?v=nPjfelBFfN0 this is me, notice that my legs are bent
http://www.youtube.com/watch?v=MzQ0LtnWFQ0 < my friend, notice how his legs are not bent. but he is short so he would not hit the floor as i would