Most people have the thumb and the index finger close to the line during the set-position - the hands are rotated to the side.
I have however always felt this to be awkward and regardless of how I distribute weight between the arms and the legs the thumbs wants to give in and I have to concentrate hard to keep balanced at all.
If I rotate the hands slightly inwards however, so that the thumb end up further behind the line and the other fingers in front of it , everything is good.
Can anybody reason why this is? Strenght, flexibility etc…