In Mark Hatmakers books he gives specific advice to use your pinky, ring and middle finger knuckles when connecting with a punch. NOT your index and middle finger. He writes that you should also connect with your whole hand and not just your first knuckles. Now i have no idea if he is right. I have looked up some drawings of what the bones in the hand look like: http://www.halecliniconline.com/images/xray.jpg From that image i get the impression he could be on to something. These are the muscles: Bottom view. http://img.sparknotes.com/figures/E/eb57ee3c0bbce61d887722fc5931002b/muscles_of_the_hand_palmar.jpg Top view. http://www.daviddarling.info/images/hand_muscles.jpg Looking at the muscles the ones behind the index and middle fingers look alot bigger and therefore may make a difference. Any thoughts? Any studys anyone knows of?