Why I hate the index finger (1980)

The hammer example made me remember something. I did some Aikido long ago, and the instructor spent quite a lot of time showing us how to grip things like sticks. As I remember it, instead of the instinctive way of just forming a fist around it, we should instead start from the little finger, wrapping the fingers one by one, but letting the index finger actually rest more along the handle than wrapping it. That way, supposedly, the grip is just as good, but more flexible and the index finger can help with control.

This is a classic way to teach use of a sword. It's also easy to feel what happens. Compare the feeling when gripping with first two fingers vs 3rd and 4th. With first 2, you will feel tension along top of forearm, whereas with the other 2 it is the underneath of forearm. This affects flexibility, softness, and thus ability to manipulate the sword.