Proper Fingertip Pushup Technique

I googled this and used the search bar, and I have not found anything definitive (too much contradicting information). I have read that these can be done on the pads or actual tips of fingers. I can do both, but I would like to know which is proper/ideal so that hyperextending or damaging my fingers can be avoided.

I most commonly see videos and pictures of people doing this exercise with their fingers fully extended on the pads of their fingers instead bending them or making a claw shape with their fingers. This is an example:

http://www.youtube.com/watch?v=dQqemLS6jh4

If anyone could post a picture of the correct technique or explain it in detail, it would be much appreciated. In addition, please instruct how to position the thumb in particular. Thanks all in advance.

I have been wondering this as well. For the moment I'm always doing them with fingers straight, bent fingers feel a lot more unstable, which could be due to my fingers not being strong enough.

I don't know anyone who doesn't do fingertip work on the pads of their fingers. working on the actual tips is quite painful for me, and i can't imagine what the benefit of doing it would be. The knuckles of your fingers should be locked out, just like your elbows should be locked during straight arm work to strengthen the joint. Even if your fingers hyper extend there's nothing wrong with that provided you go slow enough that you body gradually adapts to the stress. I'm also pretty sure that the actual position of your thumbs and the rotation of your hands is entirely optional.

Thank you.